Open Collections

UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

The effect of running on the iron requirement of females Sawchuck, Lynne Lorraine 1985

Your browser doesn't seem to have a PDF viewer, please download the PDF to view this item.

Item Metadata

Download

Media
831-UBC_1985_A7_5 S29.pdf [ 4.03MB ]
Metadata
JSON: 831-1.0077283.json
JSON-LD: 831-1.0077283-ld.json
RDF/XML (Pretty): 831-1.0077283-rdf.xml
RDF/JSON: 831-1.0077283-rdf.json
Turtle: 831-1.0077283-turtle.txt
N-Triples: 831-1.0077283-rdf-ntriples.txt
Original Record: 831-1.0077283-source.json
Full Text
831-1.0077283-fulltext.txt
Citation
831-1.0077283.ris

Full Text

THE EFFECT OF RUNNING ON THE IRON REQUIREMENT OF FEMALES by LYNNE LORRAINE SAWCHUK B . H . E c , The U n i v e r s i t y o f M a n i t o b a , 1980 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF. THE REQUIREMENTS FOR THE DEGREE OF MASTER OF PHYSICAL EDUCATION i n THE FACULTY OF GRADUATE STUDIES S c h o o l o f P h y s i c a l E d u c a t i o n We a c c e p t t h i s t h e s i s a s c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d THE UNIVERSITY OF B R I T I S H COLUMBIA O c t o b e r , 1985 L y n n e L o r r a i n e Sawchuk, 1985 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of Spnrt- R m " ^ The University of British Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 D a t e Ofltohftr 12, 19 85 DE-6(3/81) ABSTRACT To determine whether running imposes an a d d i t i o n a l i r o n cost on the female a t h l e t e , the response to an i d e n t i c a l i r o n supplementation regime (200 mg elemental iron/day f o r 12-13.5 weeks) was assessed i n two groups of i r o n d e f i c i e n t females c l a s s i f i e d as e i t h e r runners ( n = l l ) or non-runners ( n = l l ) . C r i t e r i a f o r s e l e c t i o n was i r o n d e f i c i e n c y (serum f e r r i t i n _< 20 ng/ml) with an absence of anemia (hemoglobin >^  12 g / d l ) . The response to therapy was evaluated on the b a s i s of changes i n serum f e r r i t i n and hemoglobin l e v e l s . D i e t a r y i n t a k e s , p h y s i c a l a c t i v i t y and menstruation were monitored by a l l s u b j e c t s . Runners averaged 32+8 m i l e s running/week while the non-runners remained r e l a t i v e l y sedentary d u r i n g the supplementation p e r i o d . Menstrual l o s s e s were s i m i l a r i n both groups. There was no s i g n i f i c a n t d i f f e r e n c e i n absorbable i r o n i n t a k e between the groups (p=0.10) and i n t a k e s ranged from 0.4-2.6 mg absorbable i r o n /day. Inadequate i r o n i n t a k e s were c l e a r l y demonstrated i n 62% of the d i e t a r y r e c o r d s . As expected, there was a s i g n i f i c a n t improvement i n i r o n s t a t u s over the p e r i o d of o r a l i r o n therapy. Although the average o v e r a l l change i n serum f e r r i t i n f o r non-runners was 37.1 ng/ml compared to 26.6 ng/ml f o r the runners, t h i s was not s t a t i s t i c a l l y s i g n i f i c a n t (p=0.29) due to the very l a r g e i n t e r i n d i v i d u a l v a r i a b i l i t y i n the change s c o r e s . S i m i l a r l y , t h e r e was no s i g n i f i c a n t d i f f e r e n c e i n hemoglobin between the groups when averaged over time (p=0.81) and runners and non-runners demonstrated a s i m i l a r p a t t e r n of change i n hemoglobin over the course of supplementation. Regardless of i i their a t h l e t i c practices, a l l females i n their reproductive years appear to be at high r i s k of iron deficiency, primarily due to inadequate n u t r i t i o n . Regular blood donation was also recognized as a potential contributing factor to the observed iron deficiency i n these females, p a r t i c u l a r l y in the non-runners. Because iron deficiency i s undesirable for optimal health and well-being, recognition and prevention i s highly recommended. Regular monitoring of iron status i s p a r t i c u l a r l y important in high performance athletes since a minor deficiency can pot e n t i a l l y hinder peak performance and/or lead to the development of anemia. i i i TABLE OF CONTENTS ABSTRACT i i LIST OF TABLES v i LIST OF FIGURES v i i ACKNOWLEDGEMENTS v i i i INTRODUCTION 1 METHODS 3 Subjects 3 Di e t a r y Records.... 3 Iron Supplementation 4 Blood Analyses • 5 P h y s i c a l A c t i v i t y 6 Menstruation...... • 6 S t a t i s t i c a l Analyses 6 RESULTS 8 Serum F e r r i t i n 9 Hemoglobin 9 Di e t a r y Records 10 P h y s i c a l A c t i v i t y .• 1 1 Menstruation 11 DISCUSSION 19 CONCLUSIONS. 30 RECOMMENDATIONS 32 REFERENCES 33 i v APPENDICES 3 8 1. I n i t i a l S c r e e n i n g Q u e s t i o n n a i r e 38 2. D i e t a r y Record Sheets 40 3. D a i l y M o n i t o r i n g Sheet 44 4. P h y s i c a l A c t i v i t y Record Sheet 46 5. Review of L i t e r a t u r e 48 v LIST OF TABLES I . Group P r o f i l e s 13 I I . Serum F e r r i t i n V a l u e s P r e - and D u r i n g I r o n S u p p l e m e n t a t i o n 14 I I I . Hemoglobin V a l u e s P r e - and D u r i n g I r o n S u p p l e m e n t a t i o n 15 IV. D i e t a r y & A b s o r b a b l e I r o n I n t a k e s P r e - and D u r i n g I r o n S u p p l e m e n t a t i o n 16 v i LIST OF FIGURES 1. Serum F e r r i t i n P re- and During Iron Supplementation (Mean +_ S.D.) 17 2. Hemoglobin Pre- and During Iron Supplementation (Mean +_ S.D.) 18 v i i ACKNOWLEDGEMENTS I w o u l d l i k e t o s i n c e r e l y t h a n k my a d v i s o r , D r . D. C l e m e n t , who o r i g i n a l l y i n s p i r e d t h i s w ork. H i s u n d e r s t a n d i n g , g u i d a n c e and k n o w l e d g e were m a j o r c o n t r i b u t o r s t o t h e s u c c e s s f u l c o m p l e t i o n o f t h i s i n v e s t i g a t i o n . I am a l s o g r a t e f u l t o t h e o t h e r members o f my c o m m i t t e e , D r . S. B a r r and D r . R. S c h u t z , f o r t h e i r t i m e , a d v i c e and c o n s t r u c t i v e c r i t i s i s m . S p e c i a l t h a n k s a r e e x t e n d e d t o t h e s u b j e c t s who v o l u n t e e r e d f o r t h i s s t u d y . W i t h o u t t h e i r g e n e r o u s c o o p e r a t i o n , t h i s r e s e a r c h w o u l d n o t have been p o s s i b l e . F i n a l l y , I am f o r e v e r i n d e b t e d t o my p a r e n t s f o r t h e i r c o n f i d e n c e and n e v e r e n d i n g m o r a l s u p p o r t . T h i s work was f i n a n c i a l l y s u p p o r t e d by g r a n t s f r o m Beecham L a b o r a t o r i e s ( P o i n t e C l a i r e , Quebec) and t h e N a t u r a l S c i e n c e s and E n g i n e e r i n g R e s e a r c h C o u n c i l ( N S E R C ) . v i i i INTRODUCTION In recent years, s e v e r a l i n v e s t i g a t o r s have observed a high prevalence of i r o n d e f i c i e n c y among both e l i t e and r e c r e a t i o n a l a t h l e t e s , p a r t i c u l a r l y endurance runners (Clement and Asmundson, 1982; C o l t and Heyman, 1984; Dufaux et a l . , 1981; Ehn et a l . , 1980; Hunding et a l . , 1981; Nickerson and T r i p p , 1983; Nickerson et a l . , 1985; Pakarinen, 1980; Wi s h n i t z e r et a l . , 1983). Although the p o t e n t i a l e f f e c t s of e x e r c i s e on the metabolism of n u t r i e n t s remain u n c l e a r , there has been s p e c u l a t i o n that a t h l e t e s may have an i n c r e a s e d i r o n requirement a s s o c i a t e d with t r a i n i n g ( B o t t i n g e r et a l . , 1971; Kilbom, 1971; Nickerson et a l . , 1985). P o s s i b l e e x p l a n a t i o n s f o r t h i s proposed i r o n cost of t r a i n i n g i n c l u d e an i n c r e a s e d d e s t r u c t i o n of red blood c e l l s (Davidson, 1964; Ekblom et a l . , 1972; Hunding et a l . , 1981; Lindemann et a l . , 1978; Puhl and Runyan, 1980; S h i r a k i et a l . , 1974; Yoshimura, 1970), impaired i r o n a b s o r p t i o n i n a t h l e t e s (Ehn et a l . , 1980; Clement et a l . , 1983), and/or i n c r e a s e d e l i m i n a t i o n of i r o n p o s s i b l y due to profuse sweating (Paulev et a l . , 1983; V e l l a r , 1968), hemoglobinuria/myoglobinuria, hematuria (Davidson, 1964, 1969; G i l l i g a n et a l . , 1943; S i e g e l et a l . , 1979), or el e v a t e d f e c a l i r o n l o s s (McMahon et a l . , 1984; Ruckman and Sherman, 1981; Stewart et a l . , 1984). While only minute q u a n t i t i e s of i r o n are present i n the human body, t h i s m ineral i s e s s e n t i a l f o r l i f e . As an i n t e g r a l c o n s t i t u e n t of hemoglobin, myoglobin and s e v e r a l r e s p i r a t o r y enzymes, i r o n p l a y s a v i t a l r o l e i n energy production (Fairbanks and B e u t l e r , 1983; Krause and Mahan, 1979). Approximately 1-2 mg 1 of i r o n are r e q u i r e d d a i l y t o balance t h a t which i s l o s t v i a the g a s t r o i n t e s t i n a l t r a c t , s k i n , u r i n e and m e n s t r u a t i o n . I r o n d e f i c i e n c y o c c u r s when the i r o n absorbed from the i n t e s t i n e i s l e s s than the d a i l y i r o n l o s s , l e a d i n g t o a r e d u c t i o n i n the normal i r o n c o n t e n t of the body. S i n c e i r o n s t a t u s can a f f e c t maximal p h y s i c a l performance c a p a c i t y , the i p ' d e n t i f i c a t i o n of a p o t e n t i a l l y g r e a t e r need f o r i r o n as a r e s u l t of t r a i n i n g would be of concern t o a t h l e t e s and those who a d v i s e them. In p a r t i c u l a r , a c t i v e l y t r a i n i n g females would be a t g r e a t e r r i s k of i r o n d e f i c i e n c y due to an a l r e a d y i n c r e a s e d i r o n need a s s o c i a t e d w i t h m e n s t r u a t i o n . Furthermore, the N u t r i t i o n Canada Survey (1973) i n d i c a t e d t h a t i r o n d e f i c i e n c y i s common among females i n the g e n e r a l p o p u l a t i o n and 76% of the females had i n s u f f i c i e n t d i e t a r y i r o n i n t a k e s . Whether i r o n d e f i c i e n c y i n a t h l e t e s i s due to an inadequate d i e t a r y i n t a k e of i r o n , an e x e r c i s e e f f e c t on i r o n metabolism or a c o m b i n a t i o n of b o t h , has yet to be determined. P r e v i o u s s t u d i e s have o n l y s u g gested an i r o n c o s t of t r a i n i n g but d i d not t r u l y demonstrate i t . T h e r e f o r e , the purpose of t h i s i n v e s t i g a t i o n was to t e s t the h y p o t h e s i s t h a t r u n n i n g imposes an a d d i t i o n a l i r o n c o s t on the female a t h l e t e . S p e c i f i c a l l y , the response to an i d e n t i c a l i r o n s u p p l e m e n t i o n regime was e v a l u a t e d i n i r o n d e f i c i e n t , non-anemic ru n n e r s and non-runners. I f i r o n r e q u i r e m e n t s were s i m i l a r , a s i m i l a r degree of r e p l e t i o n of i r o n s t o r e s , a s m o n i t o r e d by serum f e r r i t i n , would be a n t i c i p a t e d . C o n v e r s e l y , a l e s s e r degree of r e p l e t i o n of i r o n s t o r e s i n ru n n e r s would r e f l e c t an a d d i t i o n a l i r o n c o s t a s s o c i a t e d w i t h t r a i n i n g and t h e r e f o r e , an e l e v a t e d i r o n r e q u i r e m e n t . 2 METHODS Subjects F i f t y - t h r e e healthy females i n t h e i r r e p r o d u c t i v e years were r e c r u i t e d from a l o c a l U n i v e r s i t y campus, a sportsmedicine c l i n i c , v a r i o u s running c l u b s and blood donor c l i n i c s f o l l o w i n g approval of the r e s e a r c h by the UBC C l i n i c a l Screening Committee f o r Research and Other S t u d i e s I n v o l v i n g Human Su b j e c t s . These p o t e n t i a l s u b j e c t s i n c l u d e d both runners (_> 30 miles/week) and non-runners (maximum running a c t i v i t y < 20 minutes/day, 3 times per week). Each volunteered to be screened f o r i r o n d e f i c i e n c y by a blood t e s t . C r i t e r i a f o r s e l e c t i o n was i r o n d e f i c i e n c y (serum f e r r i t i n <20 ng/ml) with an absence of anemia (hemoglobin >12 g / d l ) . Among these v o l u n t e e r s , 26 were i d e n t i f i e d as s u i t a b l e , i r o n d e f i c i e n t candidates (13-runners, 13-non-runners) and agreed to p a r t i c i p a t e i n the study f o l l o w i n g informed consent. Each subject completed a b r i e f q u e s t i o n n a i r e (Appendix 1) to reassess and confirm t h e i r s u i t a b i l i t y f o r the study. Recent blood donors (blood donation w i t h i n the previous 4 weeks), amenorrheics and those with a h i s t o r y of e x c e s s i v e blood l o s s had been excluded from the s c r e e n i n g . D i e t a r y Records P r i o r to the i n i t i a t i o n of i r o n supplementation, d e t a i l e d 3-day ( p r e f e r a b l y 2 weekdays + 1 weekend day) d i e t a r y records were obtained from the s u b j e c t s . T h e i r usual d i e t was to be maintained f o r the d u r a t i o n of the study and another 3-day d i e t a r y record was requested f o l l o w i n g at l e a s t 6 weeks on i r o n supplementation. A l l d i e t a r y records were reviewed with each 3 subject to improve and v e r i f y the accuracy of . the r e c o r d i n g s . Information was t r a n s f e r r e d onto data sheets i n p r e p a r a t i o n f o r computerized a n a l y s i s , (Appendix 2 ). Absorbable d i e t a r y i r o n i n t a k e was c a l c u l a t e d a c c o r d i n g to a p r e v i o u s l y reported method (Monsen et a l . , 1978). Appr o p r i a t e a b s o r p t i o n f a c t o r s were chosen on the b a s i s of the magnitude of the i r o n s t o r e s c a l c u l a t e d from the serum f e r r i t i n l e v e l s at the time of r e c o r d i n g (Walters et a l . , 1973). A computerized n u t r i t i o n a l a n a l y s i s ( A c t i o n B.C. N u t r i t i o n a l E v a l u a t i o n , 1978) of each 3-day d i e t a r y record was performed and n u t r i t i o n a l c o u n s e l l i n g was provided on t e r m i n a t i o n of the study. Iron Supplementation O r a l i r o n supplementation was i n s t i t u t e d w i t h i n 2.5 weeks f o l l o w i n g the i n i t i a l s c r e e n i n g blood t e s t . The s u b j e c t s were i n s t r u c t e d to take 2 f e r r o u s fumarate capsules ( P a l a f e r , Beecham L a b o r a t o r i e s Inc., Pointe C l a i r e , Quebec) each day (200 mg elemental i r o n / d a y ) f o r a p e r i o d of 12 weeks. This corresponded to the usual supplementation regime of 180-200 mg elemental iron/day (Bothwell et a l , , 1979; C a l l e n d a r , 1982; Nimeh and Bishop, 1980). To improve t o l e r a n c e , the s u b j e c t s took 1 capsule/day f o r 4 days and then 2 capsules/day f o r the remainder of the 12 week p e r i o d . T h i s time frame was expected to be s u f f i c i e n t f o r r e s t o r a t i o n of normal red blood c e l l values and some r e p l e t i o n of i r o n s t o r e s (Clement et a l . , 1985; Fairbanks and B e u t l e r , 1983; Nimeh and Bishop, 1980). The capsules were to be ad m i n i s t e r e d i n the morning before b r e a k f a s t and l a t e at night before bed to maximize i r o n a b s o r p t i o n . To f u r t h e r enhance the 4 a b s o r p t i on, the capsules were to be ingested with 180 nil (6 oz) orange j u i c e or an e q u i v a l e n t s u b s t i t u t e . Compliance was evaluated based on the number of supplements returned and d a i l y r ecord sheets of supplement i n t a k e (Appendix 3) completed by each s u b j e c t . A compliance score was c a l c u l a t e d i n terms of the number of supplements taken over the supplementation p e r i o d . Blood Analyses With the ex c e p t i o n of one s c r e e n i n g t e s t , a l l bloodwork was performed at the UBC Health Sciences Centre H o s p i t a l , Department of Laboratory Medicine. Venous blood was drawn and analyzed f o r hemoglobin and serum f e r r i t i n . Hemoglobin was determined by a standard automated procedure using a modified cyanmethemoglobin r e a c t i o n (ELT-8, Ortho D i a g n o s t i c Systems Inc., Westwood, Mass.). The c o e f f i c i e n t of v a r i a t i o n f o r t h i s method i n t h i s l a b o r a t o r y was < 2%. Serum f e r r i t i n was determined on d u p l i c a t e samples using a 2 - s i t e immunoradiometric assay (Quantimune F e r r i t i n IRMA, BioRad C l i n i c a l L a b o r a t o r i e s , Richmond, C a l i f . ) . The c o e f f i c i e n t of v a r i a t i o n f o r t h i s method i n t h i s l a b o r a t o r y was 5%. R e l i a b i l i t y of serum f e r r i t i n was spot-checked on one t e s t sample. Measurements performed on the same sample on two separate o c c a s i o n s demonstrated acceptable r e p r o d u c i b i l t y (58 ng/ml and 59 ng/ml). F o l l o w i n g the i n i t i a l s c r e e n i n g , subsequent blood t e s t s i n c l u d i n g both hemoglobin and serum f e r r i t i n were done f o l l o w i n g 8-9 weeks of i r o n supplementation and upon t e r m i n a t i o n of the supplementation period (12-13.5 weeks). 5 P h y s i c a l A c t i v i t y A l l s u b j e c t s recorded p h y s i c a l a c t i v i t y during the supplementation p e r i o d (Appendix 4 ) . Runners i n d i c a t e d mileage run, d u r a t i o n of run and any other e x e r c i s e performed. Non-runners were encouraged to continue to remain r e l a t i v e l y i n a c t i v e while the runners were expected to maintain t h e i r usual t r a i n i n g regime. Menstruation Menstrual l o s s e s were c r u d e l y monitored by s u b j e c t i v e a p p r a i s a l . Each s u b j e c t d e s c r i b e d a l l menstrual periods experienced d u r i n g the study by r e c o r d i n g the d u r a t i o n (number of days) and amount of flow (estimated number of pads/tampons soaked). The t o t a l number of pads/tampons soaked during supplementation was c a l c u l a t e d f o r each s u b j e c t . S t a t i s t i c a l Analyses S t a t i s t i c a l a n a l y s i s was performed to evaluate any changes i n i r o n s t a t u s f o l l o w i n g supplementation and to detect any d i f f e r e n c e s between the groups i n the responses to therapy. The experimental design was a 2 (Group) by 3 (Time) f a c t o r i a l design with repeated measures on the second f a c t o r . Two 2-way analyses of v a r i a n c e were used with Group (Non-runners, Runners) and Time (Pre,During, F i n a l ) as the independent v a r i a b l e s and Serum F e r r i t i n and Hemoglobin as the dependent v a r i a b l e s . To determine whether the absorbable d i e t a r y i r o n i n t a k e was c o n s i s t e n t between the groups and d i d not change with supplementation, a 2-way a n a l y s i s of v a r i a n c e was used with Group (Non-runners, Runners) and Time (Pre, During, F i n a l ) as the 6 independent v a r i a b l e s and absorbable d i e t a r y i r o n as the dependent v a r i a b l e . S t a t i s t i c a l analyses were accomplished using Biomedical Computer Programs (BMDP) s t a t i s t i c a l r o u t i n e BMDP2V (Dixon, 1981). Menstrual data was analyzed using Student's t - t e s t s . The accepted l e v e l of s i g n i f i c a n c e f o r a l l analyses was 0.05. 7 RESULTS Twenty-two s u b j e c t s (11-runners, 11-non-runners) s u c c e s s f u l l y completed the study. The remaining su b j e c t s (2-runners, 2-non-runners) were excluded from the f i n a l analyses due to a l a c k of p a r t i c i p a t i o n i n subsequent data c o l l e c t i o n s or f a i l u r e to maintain s u f f i c i e n t running a c t i v i t y . The average age, height and weight of the runners and non-runners were s i m i l a r (Table I ) . A l l s u b j e c t s were f r e e from c o n d i t i o n s a s s o c i a t e d with e x c e s s i v e blood l o s s or a l t e r e d i r o n metabolism. Seven non-runners and two runners were blood donors, however, any rec e n t blood donations were made at l e a s t four weeks p r i o r to the i n i t i a l s c r e e n i n g blood t e s t and none of the s u b j e c t s were p r e v i o u s l y f o l l o w i n g a t h e r a p e u t i c i r o n supplementation regime. The r e g u l a r use of medications was l i m i t e d to a non-runner who took a l a x a t i v e (Metamucil) r e g u l a r l y and a non-runner who took t e t r a c y c l i n e . Both medications were taken s e p a r a t e l y from the i r o n supplements. Three s u b j e c t s (2-runners, 1-non-runner) repor t e d the o c c a s i o n a l use of anti-inflammatory medication. One non-runner noted blood i n the u r i n e f o r 1.5 days due to a bladder i n f e c t i o n . Compliance to the supplementation regime was r e l a t i v e l y high f o r both groups, averaging 98+3% (range 90-100%) and 96+7% (range 75-100%) f o r the non-runners and runners, r e s p e c t i v e l y . Except f o r one runner who demonstrated 75% compliance, a l l s u b j e c t s were at l e a s t 90% compliant to the i r o n therapy. In g e n e r a l , the supplements appeared to be w e l l t o l e r a t e d by the s u b j e c t s and only one runner complained of s u b s t a n t i a l discomfort which was 8 subsequently a l l e v i a t e d by i n g e s t i n g the capsules with a small amount of food. Serum F e r r i t i n R e s u l t s are presented i n Table I I . The data of three runners were excluded from the f i n a l a n a l y s i s as two were s u f f e r i n g from acute i n f e c t i o n s which may have f a l s e l y e l e v a t e d serum f e r r i t i n l e v e l s ( B i r g e g a r d et a l . , 1978; E l i n et a l . , 1977) and one s u b j e c t had the f i n a l blood t e s t s i x weeks l a t e . At P r e t e s t , the groups had s i m i l a r average serum f e r r i t i n l e v e l s of 12.8 ng/ml and 12.5 ng/ml f o r the non-runners(n=l1) and the runners (n=8), r e s p e c t i v e l y . Averaged over time, there was no s i g n i f i c a n t d i f f e r e n c e i n serum f e r r i t i n between the groups (p=0.29). Averaged over the groups, there was a s i g n i f i c a n t i n c r e a s e i n serum f e r r i t i n over time (p < 0.0001) with the Pre to 8 Week p e r i o d showing the g r e a t e s t i n c r e a s e . In g e n e r a l , runners and non-runners e x h i b i t e d the same i n c r e a s e and p a t t e r n of change i n serum f e r r i t i n over the d u r a t i o n of supplementation (p=0.32 f o r the Group by Time i n t e r a c t i o n ). ( F i g u r e 1). Although the average o v e r a l l change i n serum f e r r i t i n f o r non-runners was 37.1 ng/ml compared to 26.6 ng/ml f o r the runners, t h i s was not s t a t i s t i c a l l y s i g n i f i c a n t due to the very l a r g e i n t e r i n d i v i d u a l v a r i a b i l i t y i n change scores ( i e . , non-runners' gains , with the e x c e p t i o n of one s u b j e c t , ranged from 14 to 57 ng/ml, and runners' gains ranged from 6 to 45 ng/ml). Hemoglobin R e s u l t s are presented i n Table I I I . One runner who had the f i n a l blood t e s t s i x weeks l a t e was excluded from the a n a l y s i s . 9 I n i t i a l l y , the groups had s i m i l a r average hemoglobin l e v e l s of 13.4 g/dl and 13.1 g / d l f o r the non-runners ( n = l l ) and the runners (n=10), r e s p e c t i v e l y . The two groups, when averaged, showed a s i g n i f i c a n t i n c r e a s e i n hemoglobin over the supplementation p e r i o d (p=0.009). The average o v e r a l l i n c r e a s e was 0.3 g/dl over the supplementation p e r i o d . There was no s i g n i f i c a n t d i f f e r e n c e i n hemoglobin between the groups when averaged over time (p=0.81 f o r the Groups main e f f e c t ) , and runners and non-runners demonstrated a s i m i l a r p a t t e r n of change over the course of supplementation (p=0.56 f o r the Group by Time i n t e r a c t i o n ) . ( F i g u r e 2 ) . D i e t a r y Records Complete d i e t a r y r e c o r d s were obtained from 21 s u b j e c t s (11-runners, 10-non-runners), and r e s u l t s of i r o n i n t a k e are presented i n Table IV. The average absorbable i r o n i n t a k e s c a l c u l a t e d f o r the runners pre-supplementation and during supplementation were 1.4 mg and 1.2 mg, r e s p e c t i v e l y . S i m i l a r l y , non-runners recorded average absorbable i r o n i n t a k e s pre-supplementation and d u r i n g supplementation of 1.0 mg and 0.9 mg, r e s p e c t i v e l y . Absorbable i r o n i n t a k e s reported by the s u b j e c t s ranged from 0.4-2.6 mg/day. Only four s u b j e c t s (19%) recorded absorbable i r o n i n t a k e s both pre-supplementation and during supplementation of at l e a s t 1.3 mg while 62% of the d i e t a r y r ecords c l e a r l y demonstrated inadequate i r o n i n t a k e s (<1.3 mg absorbable i r o n / d a y ) . There was no s i g n i f i c a n t d i f f e r e n c e i n absorbable i r o n between the groups (p=0.10) and the absorbable i r o n i n t a k e d i d not change s i g n i f i c a n t l y during supplementation 10 (p=0.27). (Table I V ) . Computerized n u t r i t i o n a l analyses revealed an adequate average p r o t e i n i n t a k e f o r both groups. Non-runners recorded an average i n t a k e of 1.2 g protei n / k g body weight while the runners had an average i n t a k e of 1.3 g protei n / k g body weight. P h y s i c a l A c t i v i t y None of the non-runners were i n v o l v e d i n any r e g u l a r e x e r c i s e program p r i o r to or during the supplementation p e r i o d . Although two non-runners engaged i n frequent c y c l i n g (averaging 5 times/week f o r 4-7 weeks of the st u d y ) , only two reported o c c a s i o n a l running a c t i v i t y which was much l e s s than the maximum allowed f o r i n c l u s i o n . The runners maintained a high l e v e l of a c t i v i t y f o r the d u r a t i o n of the study. Average weekly running mileage was 32+8 mi l e s (range 19-50 miles) with an estimated pace ranging from 7-9 minutes/mile. Seven runners i n c l u d e d r e g u l a r 10-15 mile runs of g r e a t e r than 90 minutes d u r a t i o n . In a d d i t i o n , s e v e r a l runners f r e q u e n t l y p a r t i c i p a t e d i n other r e g u l a r p h y s i c a l a c t i v i t i e s (>30 min/session) i n c l u d i n g a e r o b i c f i t n e s s c l a s s e s , weight t r a i n i n g , b r i s k walking, c r o s s - c o u n t r y s k i i n g and c y c l i n g . None of the runners p a r t i c i p a t e d i n a marathon during the supplementation p e r i o d . Menstruation There was no s i g n i f i c a n t d i f f e r e n c e i n menstrual l o s s e s between the groups. The average number of menstrual periods recorded d u r i n g the study was 2.7+0.8 f o r the non-runners and 3.0+0.6 f o r the runners (p>0.05), and the average number of 11 pads/tampons soaked during the supplementation period was 28.5+16.2 f o r the non-runners and 23.8+16.7 f o r the runners (p>0.05). 12 TABLE I. Group P r o f i l e s * Age Height Weight A c t i v i t y Compliance ( y r s ) (cm) (kg) (miles/wk) (%) Non-runners 26.4+5.3 164.7+8.4 59.5+11.0 ** 98+3 (n-11) (19-35) (151-179) (43-86) (90-100) Runners 27.6+5.7 164.2+6.8 58.2+5.8 32+8 96+7 ( n = l l ) (20-37) (148-175) (48-67) (19-50) (75-100) * mean + SD (range) ** 2 non-runners averaged < 3 miles running/week 1 3 TABLE I I . Serum F e r r i t i n Values Pre- and During Iron Supplementation. Serum F e r r i t i n (ng/ml) Non-runners Pre 8 Weeks 12 Weeks 1 18 38 38 2 19 44 42 3 20 71 110 4 11 42 54 5 19 39 49 6 8 69 65 7 5 23 22 8 5 21 19 9 8 26 37 10 20 55 75 11 8 34 38 MEAN 12.8 42.0 49.9 +SD 6.3 17.0 25.9 Runners Pre 8 Weeks 12 Weeks 1 12 31 28 2 14 27 33 3 16 31 46 4 15 40 59 5 19 35 42 6 6 54 46 7 7 33 42 8 11 22 17 9* 12 54 130 10* 18 64 90 11* 14 42 55# MEAN** 12.5 (13. 1) 34.1 (39 .4) 39.1 +SD 4.4 (4. 1) 9.6 (13 .0) 12.9 * excluded from ANOVA ex c l u d i n g s u b j e c t s 9,10,11 (averages f o l l o w i n parentheses) 18 weeks without e x c l u s i o n s 14 TABLE I I I . Hemoglobin Values Pre- and During Iron Supplementation. Hemoglobin ( g / d l ) Non-runners Pre 8 Weeks 12 Weeks 1 12.7 12.7 12.3 2 12.9 13.7 12.4 3 13.1 13.4 13.7 4 13.8 13.1 13.5 5 15.3 15.9 14.6 6 13.1 13.3 14.2 7 13.1 13.9 13.5 8 12.4 13.1 14.4 9 12.5 13.5 13.0 10 14.3 14.3 13.9 11 13.7 14.0 13.3 MEAN 13.4 13.7 13.5 +SD 0.9 0.9 0.8 Runners Pre 8 Weeks 12 Weeks 1 13.6 14.9 15.3 2 13.0 13.6 13.0 3 13.0 14.0 14.2 4 13.3 13.4 13.0 5 13.1 13.9 13.4 6 13.1 13.7 13.1 7 12.0 13.0 12.6 8 12.9 13.5 13.6 9 12.9 13.7 14.1 10 14.2 13.2 13.7 11* 12.7 13.0 13.3 MEAN ** 13.1 13.7 13.6 +SD 0.6 0.5 0.8 * excluded from AN0VA ( f i n a l blood t e s t at 18 weeks) ** e x c l u d i n g s u b j e c t 11 15 TABLE IV. D i e t a r y & Absorbable Iron Intakes Pre- and During Iron Supplementation. Iron Intakes (mg)  Pre During Non-runners D i e t a r y Absorbable D i e t a r y Absorbable 1 9.0 0.9 8.5 0.8 2 6.3 0.5 7.9 0.6 3 13.5 1.7 14.9 1.1 4 15.9 1.6 — — 5 8.1 0.6 7.5 0.5 6 8.6 1.1 11.4 0.8 7 13.2 1.4 9.0 1.1 8 14.6 1.0 10.8 0.8 9 13.9 1.6 19.7 2.6 10 10.5 0.5 9.6 0.6 11 9.0 0.6 7.6 0.4 MEAN * 11.1 1.0 10.7 0.9 +SD 3.2 0.5 3.9 0.6 Pre During Runners D i e t a r y Absorbable D i e t a r y Absorbable 1 21.3 1.9 11.8 1.0 2 14.1 1.1 15.5 1.4 3 13.2 1.4 12.9 1.3 4 8.2 0.6 12.2 1.0 5 11.3 1.5 10.0 1.2 6 18.7 2.3 12.1 1.4 7 11.0 1.2 18.6 1.4 8 32.6 2.4 19.3 1.6 9 8.9 0.4 13.3 0.8 10 13.3 1.5 10.5 0.7 11 15.7 1.1 13.6 1.5 MEAN 15.3 1.4 13.6 1.2 +SD 6.9 0.6 3.0 0.3 * e x c l u d i n g s u b j e c t 4 16 FIGURE 1. Serum F e r r i t i n Pre- and During Iron Supplementation. (Mean + S.D.) 17 FIGURE 2. Hemoglobin Pre- and During Iron Supplementation. (Mean + S.D.) DISCUSSION The response to an i d e n t i c a l i r o n supplementation regime was assessed i n two groups of i r o n d e f i c i e n t , non-anemic females. The groups were d i f f e r e n t i a t e d only on the basi s of running a c t i v i t y . S p e c i f i c a l l y , one group engaged i n r e g u l a r d i s t a n c e running (averaging 32 miles/week) while the other group c o n s i s t e d of r e l a t i v e l y sedentary non-runners. P r i o r to supplementation, a l l s u b j e c t s had low serum f e r r i t i n l e v e l s i n d i c a t i v e of i r o n d e f i c i e n c y (Milman et a l . , 1983). F o l l o w i n g i r o n supplementation, serum f e r r i t i n and hemoglobin values s i g n i f i c a n t l y i n c r e a s e d i n the runners and non-runners c o n f i r m i n g the presence of i r o n d e f i c i e n c y at the o u t s e t . The average o v e r a l l change i n serum f e r r i t i n appeared to be g r e a t e r i n the non-runners; however, the d i f f e r e n c e between the groups was not s t a t i s t i c a l l y s i g n i f i c a n t (p=0^29) due to the l a r g e i n t e r i n d i v i d u a l v a r i a b i l i t y i n the serum f e r r i t i n responses to the i r o n therapy Because there was no d i f f e r e n c e between the groups i n the p a t t e r n or magnitude of i r o n s t o r e r e p l e t i o n , these r e s u l t s do not demonstrate an i n c r e a s e d i r o n requirement i n runners when compared to non-runners over a period of 12-13.5 weeks. Since s e v e r a l i n v e s t i g a t o r s have r e c e n t l y observed a high prevalence of i r o n d e f i c i e n c y among both e l i t e and r e c r e a t i o n a l a t h l e t e s (Clement and Asmundson, 1982; C o l t and Heyman, 1984; Dufaux et a l . , 1981; Ehn et a l . , 1980; Hunding et a l . , 1981; Nickerson and T r i p p , 1983; Nickerson et a l , 1985; Pakarinen, 1980; W i s h n i t z e r et a l . , 1983), there has been s p e c u l a t i o n that 19 t r a i n i n g may impose an a d d i t i o n a l i r o n cost on the a t h l e t e . S e v e r a l hypotheses have been proposed to e x p l a i n t h i s i n c reased need f o r i r o n , i n c l u d i n g an i n c r e a s e d d e s t r u c t i o n of red blood c e l l s (Davidson, 1964; Ekblom et a l . , 1972; Hunding et a l . , 1981; Lindemann et a l . , 1978; Puhl and Runhan, 1980; S h i r a k i et a l . , 1974; Yoshimura, 1970), i n c r e a s e d e l i m i n a t i o n of i r o n (Ehn et a l . , 1980; Clement et a l . , 1983; Paulev et a l . , 1983; McMahon et a l . , 1984; Ruckman and Sherman, 1981; Stewart et a l . , 1984) or p o s s i b l y impaired i r o n a b s o r p t i o n i n a t h l e t e s (Ehn et a l . , 1980; Clement et a l . , 1983). Evidence s u g g e s t i v e of a hemolytic process during heavy e x e r c i s e was provided i n s t u d i e s i n v o l v i n g s u b j e c t s engaged i n r i g o r o u s , prolonged e x e r c i s e (Lindemann et a l . , 1978; Radomski et a l . , 1980). Although the runners i n the present i n v e s t i g a t i o n were r e l a t i v e l y a c t i v e , t h e i r a c t i v i t y l e v e l may have been somewhat l e s s i n t e n s e than t h a t p r e v i o u l y d e s c r i b e d . On the other hand, Clement et al.(1983) r e p o r t e d depressed blood i n d i c e s s u g g e s t i v e of i n t r a v a s c u l a r hemolysis i n 3 out of 7 females with average t r a i n i n g d i s t a n c e s of 41 km/week. Hunding et al.(1981) a l s o detected a s m a l l tendency to acute hemolysis i n 3 t r a i n e d d i s t a n c e runners f o l l o w i n g a 25 km run on a hard s u r f a c e . Although these a c t i v i t y l e v e l s are more s i m i l a r to that reported i n the present study, these and e a r l i e r s t u d i e s ( G i l l i g a n et a l . , 1943; Davidson, 1964) s u f f e r e d from small sample s i z e s . Furthermore, t h i s p o t e n t i a l f o r mechanical trauma to the f e e t has l i k e l y been minimized with the advent of modern running shoes designed f o r shock a b s o r p t i o n . T h i s i s supported by D i e h l et a l . (1982) who r e c e n t l y demonstrated only minimal i n t r a v a s c u l a r 20 hemolysis and no c l i n i c a l l y s i g n i f i c a n t l y e f f e c t s on whole blood hemoglobin or hematocrit i n 8 w e l l - t r a i n e d a t h l e t e s f o l l o w i n g a 26.2 mile marathon. The runners i n the present study were con s i d e r e d to be r e l a t i v e l y w e l l - t r a i n e d and none p a r t i c i p a t e d i n marathon d i s t a n c e s during t r a i n i n g . T h e r e f o r e , i t i s u n l i k e l y that an a c c e l e r a t e d d e s t r u c t i o n of red blood c e l l s accounted f o r the i n i t i a l i r o n d e f i c i e n c y i n these runners. Furthermore, i f the runners d i d experience any degree of hemolysis and d e s t r u c t i o n of red blood c e l l s , i t was not s u f f i c i e n t to a f f e c t i r o n r e p l e t i o n over a 12-13.5 week supplementation p e r i o d . F a s t e r e l i m i n a t i o n of i r o n i n runners as compared to non-runners has a l s o been proposed to e x p l a i n the p o s s i b i l i t y of an i n c r e a s e d i r o n need i n a t h l e t e s . Male d i s t a n c e runners t r a i n i n g 120-200 km/week appeared to have a f a s t e r e l i m i n a t i o n of r a d i o a c t i v e i r o n from the body when compared to normal s u b j e c t s (Ehn et a l . , 1980). S i m i l a r l y , Clement et a l . (1983) repo r t e d a lower r e t e n t i o n of r a d i o a c t i v e i r o n i n females running an average of 41 km/week compared to values s t a t e d f o r a s i m i l a r p o p u l a t i o n of normal, n o n - e x e r c i s i n g females ( H e i n r i c h , 1970). Although p r i m a r i l y i n t e r p r e t e d as an i n d i c a t i o n of reduced a b s o r p t i o n i n the runners, the o b s e r v a t i o n may have simpley been a r e f l e c t i o n of an i n c r e a s e d e l i m i n a t i o n of r a d i o a c t i v e i r o n over the two week t e s t p e r i o d . T h i s i n c r e a s e d i r o n l o s s i n a t h l e t e s has been a t t r i b u t e d to profuse sweating (Ehn et a l . , 1980). Although i r o n l o s s v i a sweat was co n s i d e r e d to be n e g l i g i b l e i n humans, Paulev et al.(1983) demonstrated t h a t extreme sweating could account f o r s i g n i f i c a n t i r o n l o s s e s i n a t h l e t e s . Assuming sweat l o s s e s i n 21 a t h l e t e s of 1-3 1/hr ( C o l t et a l . , 1978; Paulev et a l . , 1983; V e l l a r , 1968) and a minimum i r o n c o n c e n t r a t i o n i n sweat of 0.1-0.2 mg/1 (Paulev et a l . , 1983), i n e x c e p t i o n a l cases, i r o n l o s s e s could be s i g n i f i c a n t l y i n c r e a s e d by as much as 1.0 mg/day or 100% of the d a i l y i r o n requirement of the average male (Bureau of N u t r i t i o n , 1983). Furthermore, i f the i r o n c o n c e n t r a t i o n i n sweat approaches 0.4 mg/1, as p r e v i o u s l y reported ( V e l l a r , 1968), even moderate sweat l o s s e s could s i g n i f i c a n t l y a f f e c t i r o n balance. In the present study, the runners very l i k e l y experienced g r e a t e r sweat l o s s e s due to the r e g u l a r p a r t i c i p a t i o n i n s i g n i f i c a n t l y more p h y s i c a l a c t i v i t y than the non-runners over the 12-13.5 weeks. Although the magnitude of t h i s d i f f e r e n c e cannot be q u a n t i f i e d a c c u r a t e l y from the study, i t may represent an important route of i n c r e a s e d i r o n e x c r e t i o n not matched i n the non-runners. I f t h i s was the case, i t must have been matched with an i n c r e a s e d r a t e of a b s o r p t i o n i n the runners. In a d d i t i o n to these dermal l o s s e s , s i g n i f i c a n t i r o n l o s s e s i n a t h l e t e s may r e s u l t from i n c r e a s e d f e c a l i r o n l o s s , hemoglobinuria/myoglobinuria or hematuria. E l e v a t e d f e c a l i r o n e x c r e t i o n was observed i n swimming r a t s (Ruckman and Sherman, 1981) and accounted f o r by the p o s s i b i l i t y of an i n c r e a s e d s e c r e t i o n of endogenous i r o n i n the b i l e . Recently, g a s t r o i n t e s t i n a l (GI) blood l o s s has been documented i n marathon runners (McMahon et a l . , 1984) and a d u l t male and female runners (Stewart et a l . , 1984). F e c a l hemoglobin l e v e l s i n c r e a s e d i n 20 out of 24 runners f o l l o w i n g 10-42 km r a c e s . D a i l y s t o o l l o s s e s i n the runners were c a l c u l a t e d to be 1.2 ml of whole blood or 0.6 mg of elemental i r o n i n 24 hours. In 7 runners,these f e c a l 22 hemoglobin l o s s e s were g r e a t e r than 3.0 mg of hemoglobin per gram of s t o o l which corresponded to g r e a t e r than 3 ml of blood (1.5 rag elemental i r o n ) l o s t through the GI t r a c t i n one day (Stewart et a l . , 1984). Furthermore, 7 of 32 Boston marathoners had guaic p o s i t i v e s t o o l f o r blood i n d i c a t i v e of GI blood l o s s a f t e r a i marathon (McMahon et a l . , 1984). A prolonged d a i l y l o s s of only a few m i l l i l i t e r s of blood w i l l i n e v i t a b l y lead to d e p l e t i o n of i r o n s t o r e s and p o s s i b l y anemia (Bothwell et a l . , 1979). None of the runners i n the present study p a r t i c i p a t e d i n a marathon during the suppelmentation p e r i o d , although s e v e r a l engaged i n r e g u l a r s i n g l e runs exceeding 90 minutes d u r a t i o n and c o v e r i n g d i s t a n c e s of 10-15 miles at one time. While none of the runners r e p o r t e d a h i s t o r y of blood l o s s i n the s t o o l s when questioned p r i o r to supplementation, i t i s p o s s i b l e that some GI blood l o s s was e l i c i t e d from the r e p o r t e d l e v e l of a c t i v i t y (32 miles/week). T h i s was not s u b s t a n t i a t e d i n the present i n v e s t i g a t i o n because s t o o l s darkened by the i r o n supplementation masked any s i g n s of o v e r t blood l o s s and t e s t s f o r o c c u l t blood were not performed. Hemolysis or damage to the muscle c e l l w a l l a s s o c i a t e d with heavy e x e r c i s e may r e s u l t i n e x c e s s i v e amounts of f r e e c i r c u l a t i n g hemoglobin and myoglobin which can be excreted i n the u r i n e (Davidson, 1964,1969; G i l l i g a n et a l . , 1943; S i e g e l et a l . , 1979). Furthermore, whole blood may be r e l e a s e d i n the u r i n e (hematuria) f o l l o w i n g p h y s i c a l e x e r t i o n . U r i n a l y s e s i n a group of 50 male Boston marathoners showed gross or m i c r o s c o p i c hematuria i n 9 cases ( S i e g e l et a l , 1979). Other i n v e s t i g a t o r s have a l s o r e p o r t e d cases of hematuria i n long d i s t a n c e runners 23 and marathoners ( B l a c k l o c k , 1977; B o i l e a u et a l . , 1980). Blood l o s s may occur m i c r o s c o p i c a l l y and remain undetected or i t may appear as g r o s s l y red u r i n e . Only one s u b j e c t reported blood l o s s i n the u r i n e f o r a s h o r t p e r i o d of 1.5 days and t h i s was a non-runner with a bladder i n f e c t i o n . M i c r o s c o p i c blood l o s s was not monitored. Menstrual blood l o s s v a r i e s markedly from one woman to another and i t i s d i f f i c u l t to evaluate by q u e s t i o n i n g (Bothwell and C h a r l t o n , 1981). Ne v e r t h e l e s s , an attempt was made at the o u t s e t of the present study to i n c l u d e only those females e x p e r i e n c i n g r e l a t i v e l y normal menstruation with r e g u l a r c y c l e s , e x c l u d i n g amenorrheics and those with e x c e s s i v e menstrual blood l o s s . As a n t i c i p a t e d , both groups recorded a s i m i l a r average number of menstrual p e r i o d s during the study and the estimated amount of flow was not s i g n i f i c a n t l y d i f f e r e n t between the groups. T h e r e f o r e , the average i r o n l o s s v i a menstruation was not a c o m p l i c a t i n g f a c t o r i n the i n t e r p r e t a t i o n of the present r e s u l t s . The a b s o r p t i o n of i r o n can s i g n i f i c a n t l y i n f l u e n c e i r o n r e p l e t i o n . Normally, i r o n a b s o r p t i o n i s enhanced i n p r o p o r t i o n to inadequate i r o n s t o r e s ( H e i n r i c h , 1970). Based on s i m i l a r i n i t i a l serum f e r r i t i n l e v e l s and s i m i l a r responses to an i d e n t i c a l t r i a l of i r o n therapy, i t would appear that both groups were i n an e a r l y stage of i r o n d e f i c i e n c y (Bothwell et a l . , 1979; Cook, 1982; H e i n r i c h , 1970) and i r o n a b s o r p t i o n should have been a d j u s t e d e q u a l l y i n both. There i s reason to b e l i e v e that t h i s may not have o c c u r r e d i n the present s i t u a t i o n . Although there i s l i t t l e doubt t h a t serum f e r r i t i n i s a r e l i a b l e i n d i c a t o r of 24 the amount of i r o n s t o r e s i n i r o n d e f i c i e n t and normal s u b j e c t s (Bezwoda et al.,1979; Jacobs, 1977; Walters et a l . , 1973), there has been some concern that serum f e r r i t i n l e v e l s may be f a l s e l y e l e v a t e d i n d i s t a n c e runners f o l l o w i n g strenuous e x e r c i s e (Dickson, 1982). At the completion of a 56 km road race, runners had e l e v a t e d serum f e r r i t i n l e v e l s which f e l l s i g n i f i c a n t l y a f t e r a 2 week r e s t p e r i o d . S i m i l a r l y , an acute e f f e c t of e x e r c i s e was observed i n cadets p a r t i c i p a t i n g i n a strenuous 5 day ranger course (Vidnes and Opstad, 1981). Even though the 2 groups i n the present study had s i m i l a r average i n i t i a l serum f e r r i t i n l e v e l s i t i s p o s s i b l e that the runners demonstratd f a l s e l y e l e v a t e d l e v e l s i n response to t r a i n i n g . Consequently, they may have a c t u a l l y been more i r o n d e f i c i e n t than i n d i c a t e d by the present r e s u l t s and the a s s o c i a t e d i r o n a b s o r p t i o n may have been i n c r e a s e d to a g r e a t e r degree than t h a t experienced by the non-runners. Because the i r o n therapy provided ample i r o n to s a t i s f y an i n c r e a s e d a b s o r p t i o n l e v e l , i t i s p o s s i b l e that the runners covered any g r e a t e r i r o n demands r e l a t e d to t r a i n i n g by simply absorbing e x t r a i r o n during the supplementation p e r i o d . Due to the absence of s u f f i c i e n t data on i r o n a b s o r p t i o n i n i r o n d e f i c i e n t a t h l e t e s , t h i s proposed e x p l a n a t i o n must be regarded as purely s p e c u l a t i v e . Furthermore, the l i m i t e d evidence i n e x i s t e n c e has not c l e a r l y demonstrated an adequate i r o n a b s o r p t i o n response i n i r o n d e f i c i e n t a t h l e t e s when compared to i r o n d e f i c i e n t c o n t r o l s (Ehn et a l . , 1980) or s i m i l a r n o n - e x e r c i s i n g normals (Clement et a l . , 1983). Despite the l a c k of c o n c l u s i v e r e s u l t s , these s t u d i e s 25 suggest the p o s s i b i l i t y of some a b s o r p t i o n d i s t u r b a n c e i n those engaged i n p h y s i c a l a c t i v i t y and appear to be c o n t r a r y to previous o b s e r v a t i o n s i n i r o n d e f i c i e n t groups ( H e i n r i c h , 1970). T h e r e f o r e , f u r t h e r i n f o r m a t i o n r e g a r d i n g i r o n a b s o r p t i o n i n a t h l e t e s i s necessary before a complete assessment of the present f i n d i n g s can be made. The response to 12-13.5 weeks of i r o n therapy (200 mg elemental iron/day) was e v a l u a t e d i n t h i s i n v e s t i g a t i o n p r i m a r i l y on the b a s i s of changes i n serum f e r r i t i n . While hemoglobin was a l s o determined, t h i s measurement may be i n f l u e n c e d by s e v e r a l u n c o n t r o l l e d f a c t o r s (Dacie and Lewis, 1975) and i t was i n c l u d e d mainly to monitor an absence of anemia i n the s u b j e c t s p r i o r to and during the supplementation p e r i o d . N e v e r t h e l e s s , both parameters showed a s i g n i f i c a n t i n c r e a s e f o l l o w i n g the t r i a l of i r o n therapy and t h i s response i s c o n s i d e r e d d i a g n o s t i c of i r o n d e f i c i e n c y (Fairbanks and B e u t l e r , 1983). As suspected, the changes were more marked i n the serum f e r r i t i n l e v e l s , which had i n i t i a l l y i n d i c a t e d severe i r o n s t o r e d e p l e t i o n i n both groups, while a l l hemoglobin l e v e l s were i n the normal range throughout the study. Contrary to the c o n c l u s i o n s reached by Magnusson et al.(1984a, 1984b), i t appears from the present f i n d i n g s t h a t many runners do s u f f e r from a t r u e i r o n d e f i c i e n c y which responds f a v o u r a b l y to o r a l i r o n therapy. Due to the l a r g e v a r i a b i l i t y i n the i n d i v i d u a l serum f e r r i t i n responses over the p e r i o d of supplementation, i t was not p o s s i b l e to d e t e c t a s i g n i f i c a n t d i f f e r e n c e between the groups i n the magnitude of change.Some i n t e r i n d i v i d u a l v a r i a b i l i t y was a n t i c i p a t e d , however, the present r e s u l t s were somewhat co n f u s i n g 26 w i t h observed changes i n serum f e r r i t i n over the same s u p p l e m e n t a t i o n regime r a n g i n g from 6-90 ng/ml. T h e r e f o r e , the c o r r e c t i o n of i r o n d e f i c i e n c y by r e p l e t i o n of i r o n s t o r e s must be c o n s i d e r e d independent of a c t i v i t y s t a t u s i n the p r e s e n t i n v e s t i g a t i o n . I n c o n t r a s t t o the i n i t i a l h y p o t h e s i s , these r u n n e r s d i d not c l e a r l y demonstrate any i n c r e a s e d i r o n need beyond t h a t e x p e r i e n c e d by non-runners over the same p e r i o d of t i m e . Based on t h i s outcome, the i r o n d e f i c i e n t c o n d i t i o n i n the r u n n e r s cannot be a t t r i b u t e d t o an e x t r a i r o n c o s t a s s o c i a t e d w i t h t r a i n i n g . C e r t a i n l y , a c o n t r i b u t i n g f a c t o r t o the d e p l e t e d i r o n s t o r e s i n both groups would be an i n a d e q u a t e d i e t a r y i n t a k e . N u t r i t i o n a l i n f o r m a t i o n from a 3-day d i e t a r y r e c o r d p r o v i d e s a r e a s o n a b l e a p p r o x i m a t i o n of an i n d i v i d u a l ' s d i e t a r y i n t a k e ( C ampbell and MacFayden, 1984) and was used i n the p r e s e n t i n v e s t i g a t i o n t o determine the adequacy of the s u b j e c t s 1 d i e t s i n terms of p r o t e i n and i r o n i n t a k e . The i n f o r m a t i o n was r e p r e s e n t a t i v e of the i n t a k e s p r i o r t o and d u r i n g s u p p l e m e n t a t i o n . A l t h o u g h average p r o t e i n i n t a k e s were adequate and t h e average a b s o r b a b l e i r o n i n t a k e s were m a r g i n a l (Bureau of N u t r i t i o n , 1983), 62% of the d i e t a r y r e c o r d s demonstrated a b s o r b a b l e i r o n i n t a k e s below t h a t recommended f o r females i n t h i s age group (Bureau of N u t r i t i o n , 1983). T h i s r e s u l t was not s u r p r i s i n g as n u t r i t i o n a l i r o n d e f i c i e n c y i s a widespread problem i n f e m a l e s . A c c o r d i n g t o the N u t r i t i o n Canada Survey (1973), 76% of females i n the g e n e r a l p o p u l a t i o n had i n s u f f i c i e n t d i e t a r y i r o n i n t a k e s . S i m i l a r l y , an i n v e s t i g a t i o n of endurance r u n n e r s 27 found that 90% of the females had i r o n i n t a k e s below the recommendation (Clement and Asmundson, 1982). - In the present i n v e s t i g a t i o n , the average i r o n i n t a k e ranged from 0.9-1.4 mg absorbable iron/day between the groups. While the average woman r e q u i r e s approximately 1.3 mg absorbable iron/day (0.67 mg iron/day to cover b a s a l l o s s e s and an a d d i t i o n a l 0.63 mg/day to cover average menstrual l o s s e s ) , some may r e q u i r e as much as 2.4 mg/day due to g r e a t e r menstrual l o s s e s . C o n s i d e r i n g the group averages and the high prevalence of low i n d i v i d u a l i n t a k e s , i t i s e v ident that an inadequate d i e t a r y i r o n i n t a k e was l i k e l y the major c o n t r i b u t i n g cause of the i r o n d e f i c i e n c y observed i n these females. Another f a c t o r i n the e t i o l o g y of i r o n d e f i c i e n c y concerns the s i g n i f i c a n t i r o n l o s s through frequent blood donations (Jacob et a l . , 1980; Milman and Sondergaard, 1984; Skikne et a l . , 1984; Strandberg Pederson and M o r l i n g , 1978). A s u b s t a n t i a l i r o n l o s s (approximately 250 mg i r o n ) occurs at each blood donation and the d a i l y i r o n requirement may i n c r e a s e 3- to 4 - f o l d with four donations per year (Bothwell et a l . , 1979). T h i s was p a r t i c u l a r l y r e l e v a n t i n the non-runner group which i n c l u d e d more r e g u l a r blood donors. In summary, the present f i n d i n g s d i d not support the i n i t i a l h y pothesis t h a t runners have an i n c r e a s e d i r o n requirement as a r e s u l t of heavy t r a i n i n g . Although i r o n d e f i c i e n t , non-anemic runners and non-runners showed s i g n i f i c a n t i n c r e a s e s i n i r o n s t o r e s f o l l o w i n g supplementation, there was no d i f f e r e n c e between the groups. Regardless of t h e i r a t h l e t i c p r a c t i c e s , a l l females i n t h e i r r e p r o d u c t i v e years appear to be a t high r i s k of i r o n d e f i c i e n c y , p r i m a r i l y due to inadequate n u t r i t i o n . Regular blood 28 d o n a t i o n was a l s o r e c o g n i z e d as a c o n t r i b u t i n g f a c t o r to i r o n d e f i c i e n c y . 29 CONCLUSIONS Over a pe r i o d of approximately 3 months of i r o n replacement, i r o n d e f i c i e n t , non-anemic female runners t r a i n i n g an average d i s t a n c e of 32 miles/week d i d not demonstrate a s i g n i f i c a n t d i f f e r e n c e i n i r o n r e p l e t i o n when compared to r e l a t i v e l y i n a c t i v e non-runners who were e q u a l l y i r o n d e f i c i e n t . Although g r e a t e r i r o n l o s s e s i n the runners r e l a t i v e to the non-runners were p o s s i b l e due to i n c r e a s e d sweat l o s s e s , hemoglobinuria/myoglobinuria, hematuria and/or g a s t r o i n t e s t i n a l blood l o s s e s a s s o c i a t e d with p h y s i c a l e x e r t i o n , none of these were i n d i r e c t l y i m p l i c a t e d as i r o n r e p l e t i o n was not s i g n i f i c a n t l y d i f f e r e n t between the groups. Undoubtedly, the major c o n t r i b u t i n g f a c t o r to the depleted i r o n s t o r e s i n both groups was an inadequate n u t r i t i o n a l i n t a k e . On the average, runners and non-runners had s i m i l a r absorbable i r o n i n t a k e s which were marginal i n terms of the c u r r e n t recommendations. Furthermore, the a d d i t i o n a l i r o n l o s s a s s o c i a t e d with blood donation would make i t extremely d i f f i c u l t f o r the average female blood donor to adequately meet her i r o n requirements. T h i s was l i k e l y another c o n t r i b u t i n g f a c t o r to the i r o n d e f i c i e n c y i n these females, many of whom were blood donors. Although t h i s study d i d not support the theory that a t h l e t e s have an i n c r e a s e d i r o n requirement a s s o c i a t e d with t r a i n i n g , i t demonstrated that high dosage i r o n supplementation (200 mg elemental iron/day) i n i r o n d e f i c i e n t , non-anemic females can s i g n i f i c a n t l y improve i r o n s t a t u s over a p e r i o d of 12-13.5 weeks. Furthermore, i t confirms the high frequency of inadequate 30 a v a i l a b l e d i e t a r y i r o n i n the d i e t s of females i n t h e i r r e p r o d u c t i v e years. Regardless of t h e i r a t h l e t i c p r a c t i c e s , a l l menstruating females appear to be at high r i s k of i r o n d e f i c i e n c y . Because t h i s c o n d i t i o n i s u n d e s i r a b l e f o r optimal h e a l t h and w e l l - b e i n g , r e c o g n i t i o n and p r e v e n t i o n i s s t r o n g l y recommended. From the a t h l e t e ' s standpoint, the consequences of an i r o n d e f i c i e n c y c o u l d be considered more s i g n i f i c a n t s i n c e n u t r i e n t d e f i c i e n c i e s can undermine the attainment of peak performances. T h e r e f o r e , r e g u l a r monitoring of the i r o n s t a t u s of a t h l e t e s i s s t i l l warranted to i d e a l l y prevent i r o n d e f i c i e n t c o n d i t i o n s or provide d e t e c t i o n i n the e a r l y s t a g e s . 31 RECOMMENDATIONS 1. Adequate n u t r i t i o n a l intakes, s p e c i f i c a l l y related to s u f f i c i e n t absorbable dietary iron, must be emphasized for women in t h e i r reproductive years as poor iron n u t r i t i o n appears to be the major contributing factor to the high frequency of iron deficiency observed i n t h i s population. 2. Regular monitoring of the iron status of high performance athletes involved i n some endurance training i s recommended to ensure optimal performance a b i l i t y . This should include routine examination of serum f e r r i t i n and hemoglobin levels i n addition to p e r i o d i c a l dietary analyses of the athlete's n u t r i t i o n a l intake. If an iron d e f i c i e n t condition i s detected, prompt intervention involving n u t r i t i o n a l counselling and/or iron supplementation i s necessary. 3. Using a similar protocol to the present study, repletion or depletion of iron stores i n runners compared to non-runners could be investigated i n a larger group for a more extended period of time. This may reduce the v a r i a b i l i t y within the groups and the longer follow-up may be necessary for the detection of a potential difference between groups. 4. Blood donor' c l i n i c s should consider further research into the effectiveness of including serum f e r r i t i n analyses as a means of determining the need for iron repletion i n regular blood donors, es p e c i a l l y females in t h e i r reproductive years. 32 REFERENCES A c t i o n B . C . N u t r i t i o n E v a l u a t i o n ( 1 9 7 8 ) . A v a i l a b l e by w r i t i n g : C o m p u t e r i z e d N u t r i t i o n A n a l y s i s , c / o Downtown YMCA, 955 B u r r a r d S t . , V a n c o u v e r , B . C . , C a n a d a , V6Z 1 Y 2 . B e z w o d a , W . , T . B o t h w e l l , J . T o r r a n c e , A . M a c P h a i l , R. C h a r l t o n , G . K a y , and J . L e v i n . T h e r e l a t i o n s h i p be tween marrow i r o n s t o r e s , p l a s m a f e r r i t i n c o n c e n t r a t i o n s and i r o n a b s o r p t i o n . S c a n d . J . H a e m a t o l . 2 2 : 1 1 3 - 1 2 0 , 1 9 7 9 . B i r g e g a r d , G . , R. H a l l g r e n , A . K i l l a n d e r , A . S t r o m b e r g , P . V e n g e , and L . W i d e . Serum f e r r i t i n d u r i n g i n f e c t i o n . S c a n d . J .  H a e m a t o l . 2 1 : 3 3 3 - 3 4 0 , 1 9 7 8 . B l a c k l o c k , N . B l a d d e r t r a u m a i n t h e l o n g d i s t a n c e r u n n e r : " 1 0 , 0 0 0 m e t r e s h a e m a t u r i a " . B r i t . J . U r o l . 4 9 : 1 2 9 - 1 3 2 , 1 9 7 7 . B o i l e a u , M . , E . F u c h s , J . B a r r y , and C . H o d g e s . S t r e s s h e m a t u r i a : a t h l e t i c p s e u d o n e p h r i t i s i n m a r a t h o n e r s . U r o l o g y 1 5 ( 5 ) : 4 1 7 - 4 7 4 , 1 9 8 0 . B o t h w e l l , T . H . and R. C h a r l t o n . I r o n D e f i c i e n c y i n Women- A_ R e p o r t o f t h e I n t e r n a t i o n a l N u t r i t i o n a l A n a e m i a C o n s u l t a t i v e  G r o u p ( I N A C G ) . A p r i l , 1 9 8 1 , p p . 1 - 5 7 . B o t h w e l l , T . H . , R .W. C h a r l t o n , J . D . C o o k , and C A . F i n c h . I r o n  M e t a b o l i s m i n M a n . O x f o r d , B l a c k w e l l S c i e n t i f i c P u b l i c a t i o n s , 1 9 7 9 , p p . 1 - 8 1 . B o t t i g e r , L . D . , A . N y b e r g , I. A s t r a n d , and P - 0 . A s t r a n d . I r o n a d m i n i s t r a t i o n t o h e a l t h y , p h y s i c a l l y v e r y a c t i v e s t u d e n t s . N o r d . M e d . 8 5 : 3 9 6 - 3 9 8 , 1 9 7 1 . B u r e a u o f N u t r i t i o n R e s e a r c h . Recommended N u t r i e n t I n t a k e s f o r C a n a d i a n s ( 4 t h E d ) . O t t a w a , H e a l t h and W e l f a r e C a n a d a , 1 9 8 3 . C a l l e n d e r , S . T r e a t m e n t o f i r o n d e f i c i e n c y . C l i n . H a e m a t o l . 1 1 ( 2 ) : 3 2 7 - 3 3 8 , 1 9 8 2 . C a m p b e l l , M . L . and K . L . M a c F a y d e n . N u t r i t i o n k n o w l e d g e , b e l i e f s and d i e t a r y p r a c t i c e s o f c o m p e t i t i v e s w i m m e r s . C a n . Home E c . J . 3 4 ( l ) : 4 7 - 5 2 , 1 9 8 4 . C l e m e n t , D . B . and R . C . A s m u n d s o n . N u t r i t i o n a l i n t a k e and h e m a t o l o g i c a l p a r a m e t e r s i n e n d u r a n c e r u n n e r s . P h y s .  S p o r t s m e d . 1 0 ( 3 ) : 3 7 - 4 3 , 1 9 8 2 . C l e m e n t , D . B . , J . E . T a u n t o n , D. M c K e n z i e , D. L y s t e r , L . S a w c h u k , and J . P . W i l e y . I r o n a b s o r p t i o n i n i r o n d e f i c i e n t , e n d u r a n c e t r a i n e d f e m a l e s . U n p u b l i s h e d , 1 9 8 3 . 33 Clement, D.B., J.E. Taunton, D. McKenzie, L.L Sawchuk, and J.P. Wiley. High- and low-dosage i r o n supplementation i n i r o n d e f i c i e n t , endurance t r a i n e d females. In Katch, F. (Ed). Sport, H e a l t h , and N u t r i t i o n . Champaign, Human K i n e t i c s P u b l i s h e r s , 1985. C o l t , E. and B. Heyman. Low f e r r i t i n l e v e l s i n runners. J .  Sports Med. 24:13-17, 1984. Cook, J . C l i n i c a l e v a l u a t i o n of i r o n d e f i c i e n c y . Semin.  Hemat. 19(1):6-18, 1982. Davidson, R.J.L. E x e r t i o n a l haemoglobinuria: a r e p o r t on three cases with s t u d i e s on the haemolytic mechanism. C l i n . Path. 17:536-540, 1964. Davidson, R.J.L. March or e x e r t i o n a l haemoglobinuria. Semin.  Hematol. 6:150-161, 1969. Dacie, J . and S. Lewis. P r a c t i c a l Haematology,5th ed. New York, C h u r c h i l l L i v i n g s t o n e , 1975, pp. 10-20. Dickson, D.H., R.L. W i l k i n s o n , and T.D. Noakes. E f f e c t s of ultra-marathon t r a i n i n g and r a c i n g on hematologic parameters and serum f e r r i t i n l e v e l s i n w e l l - t r a i n e d a t h l e t e s . I n t . J .  Sports Med. 3(2):111-117, 1982. D i e h l , L., W. B u t l e r , E. Ferguson, and E. Schoomaker. I n t r a v a s c u l a r hemolysis i n marathon runners. C l i n . Res. 30:314, 1982. Dixon, W.J. (Ed) BMDP- S t a t i s t i c a l Software Los Angeles, U n i v e r s i t y of C a l i f o r n i a Press, 1981, pp. 359-387. Dufaux, B., A. Hoederath, I. S t r e i t b e r g e r , W. Hollman, and G. Assman. Serum f e r r i t i n , t r a n s f e r r i n , haptoglobin and i r o n i n middle- and l o n g - d i s t a n c e runners, e l i t e rowers and p r o f e s s i o n a l r a c i n g c y c l i s t s . I n t . J . Sports Med. 2(1):43-46, 1981. Ehn, L., B. Carlmark, and S. Hoglund. Iron s t a t u s i n a t h l e t e s i n v o l v e d i n i n t e n s e p h y s i c a l a c t i v i t y . Med. S c i . Sports  Exer. 1 2 ( l ) : 6 l - 6 4 , 1980. Ekblom, B., A. Goldbarg, and B. G u l l b r i n g . Response to e x e r c i s e a f t e r blood l o s s and r e i n f u s i o n . J_^ Appl. P h y s i o l . 33:175-180, 1972. E l i n , R., S. W olff, and C. F i n c h . E f f e c t of induced fever on serum i r o n and f e r r i t i n c o n c e n t r a t i o n s i n man. Blood 49(1):147-153, 1977. F a i r b a n k s , V. and E. B e u t l e r . Iron d e f i c i e n c y . In W i l l i a m s , W., E. B e u t l e r , A. E r s l e v , and M. Lichtman (Eds) Hematology,  3rd ed. New York, McGraw-Hill Book Company, 1983, pp.466-84. 34 G i l l i g a n , D . R . , M . D . A l t s c h u l e , and E . M . K a t e r s k y . P h y s i o l o g i c i n t r a v a s c u l a r h e m o l y s i s o f e x e r c i s e . H e m o g l o b i n e m i a and h e m o g l o b i n u r i a f o l l o w i n g c r o s s - c o u n t r y r u n s . J . C l i n .  I n v e s t . 2 2 : 8 5 9 , 1 9 4 3 . H e i n r i c h , H . C . I n t e s t i n a l i r o n a b s o r p t i o n i n man- m e t h o d s o f m e a s u r e m e n t , d o s e r e l a t i o n s h i p , d i a g n o s t i c and t h e r a p e u t i c a p p l i c a t i o n s . In H a l l b e r g , L . , H . G . H a r w e r t h , and A . V a n e t t i ( E d s ) . I r o n D e f i c i e n c y : P a t h o g e n e s i s , C l i n i c a l  A s p e c t s . T h e r a p y . New Y o r k , A c a d e m i c P r e s s , 1 9 7 0 , p p . 2 1 3 -2 9 6 . H u n d i n g , A . , R. J o r d a l , and P . P a u l e v . R u n n e r ' s a n e m i a and i r o n d e f i c i e n c y . A c t a M e d . S c a n d . 2 0 9 : 3 1 5 - 3 1 8 , 1 9 8 1 . J a c o b , R . , H . S a n d s t e a d , L . K l e v a y , and L . J o h n s o n . U t i l i t y o f s e r u m f e r r i t i n a s a m e a s u r e o f i r o n d e f i c i e n c y i n n o r m a l m a l e s u n d e r g o i n g r e p e t i t i v e p h l e b o t o m y . B l o o d 5 6 : 7 8 6 - 7 9 1 , 1 9 8 0 . J a c o b s , A . Serum f e r r i t i n and i r o n s t o r e s . F e d . P r o c . 3 6 ( 7 ) : 2 0 2 4 - 2 0 2 7 , 1 9 7 7 . K i l b o m , A . P h y s i c a l t r a i n i n g w i t h s u b m a x i m a l i n t e n s i t i e s i n women: r e a c t i o n t o e x e r c i s e and o r t h o s t a s i s . S c a n d • J •  C l i n . I n v e s t . 2 8 : 1 4 1 - 1 6 1 , 1 9 7 1 . K r a u s e , M. and L . M a h a n . F o o d , N u t r i t i o n and D i e t T h e r a p y . P h i l a d e l p h i a , W . B . S a u n d e r s C o m p a n y , 1 9 7 9 , p p . 1 2 9 - 1 3 5 . L i n d e m a n n , R . , R. E k a n g e r , P . K . O p s t a d , M. Nummestad , and R. L j o s l a n d . H e m a t o l o g i c a l c h a n g e s i n n o r m a l men d u r i n g p r o l o n g e d s e v e r e e x e r c i s e . Am. C o r r e c t . T h e r . J . 3 2 ( 4 ) : 107 -111 , 1 9 7 8 . M a g n u s s o n , B . , L . H a l l b e r g , L . R o s s a n d e r , and B . , S w o l i n . I r o n m e t a b o l i s m and " s p o r t s a n e m i a " . I. A s t u d y o f s e v e r a l i r o n p a r a m e t e r s i n e l i t e r u n n e r s w i t h d i f f e r e n c e s i n i r o n s t a t u s . A c t a M e d . S c a n d . 2 1 6 : 1 4 9 - 1 5 5 , 1 9 8 4 a . M a g n u s s o n , B . , L . H a l l b e r g , L . R o s s a n d e r , and B . S w o l i n . I r o n m e t a b o l i s m and " s p o r t s a n e m i a " . I I . A h e m a t o l o g i c a l c o m p a r i s o n o f e l i t e r u n n e r s and c o n t r o l s u b j e c t s . A c t a M e d .  S c a n d . 2 1 6 : 1 5 7 - 1 6 4 , 1 9 8 4 b . M c M a h o n , L . F . , M . J . R y a n , D. L a r s o n , R . L . F i s h e r . O c c u l t g a s t r o i n t e s t i n a l b l o o d l o s s i n m a r a t h o n r u n n e r s . A n n . I n t .  M e d . 1 0 0 : 8 4 6 - 8 4 7 , 1 9 8 4 . M i l m a n , N . and M. S o n d e r g a a r d . I r o n s t o r e s i n ma le b l o o d d o n o r s e v a l u a t e d by s e r u m f e r r i t i n . T r a n s f u s i o n 2 4 : 4 6 4 - 4 6 8 , 1 9 8 4 . M i l m a n , N . , N . S t r a n d b e r g P e d e r s e n , V i s f e l d t , J . Serum f e r r i t i n i n h e a l t h y D a n e s : r e l a t i o n t o marrow h a e m o s i d e r i n i r o n s t o r e s . D a n . M e d . B u l l . 3 0 : 1 1 5 - 1 2 0 , 1 9 8 3 . 35 Monsen, E., L. H a l l b e r g , J . L a y r i s s e , D. Hegsted, J . Cook, W. Mertz, and C. F i n c h . E s t i m a t i o n of a v a i l a b l e d i e t a r y i r o n . Am. J . C l i n . Nutr. 31:134-141, 1978. Nickerson, H.J. and A. T r i p p . Iron d e f i c i e n c y i n adolescent c r o s s - c o u n t r y runners. Phys. Sportsmed. l l ( 6 ) : 6 0 - 6 6 , 1983. Nickerson, H.J., M. Holubets, A. T r i p p , and W. P i e r c e . Decreased i r o n s t o r e s i n high school female runners. Am. J . C h i l d .  D i s e a s e s . Accepted f o r p u b l i c a t i o n , 1985. Nimeh, N. and R.C. Bishop. D i s o r d e r s of i r o n metabolism. Med.  C l i n . N. Amer. 64(4):631-645, 1980. N u t r i t i o n Canada. N u t r i t i o n - A^  N a t i o n a l P r i o r i t y . Ottawa, Information Canada, 1973. Pakarinen, A. F e r r i t i n i n sp o r t medicine. N o r d i c l a b - N e w s l e t t e r s 4:20-28, 1980. Paulev, P., R. J o r d a l , and N. Pedersen. Dermal e x c r e t i o n of i r o n i n i n t e n s e l y t r a i n i n g a t h l e t e s . C l i n . Chem. Acta 127:19-27, 1983. Puhl, J.L. and W.S. Runyan. Hematological v a r i a t i o n s during a e r o b i c t r a i n i n g of c o l l e g e women. Res. Quart. Exer. Sport 51(3) :533-541, 1980. Radomski, M.W., B.H. S a b i s t o n , and P. Is o a r d . Development of " s p o r t s anemia" i n p h y s i c a l l y f i t men a f t e r d a i l y s u s t a ined sub-maximal e x e r c i s e . A v i a t . Space E n v i r o n . Med. 51:41-45, 1980. Ruckman, K. and A. Sherman. E f f e c t s of e x e r c i s e on i r o n and copper metabolism i n r a t s . J . Nutr. 111:1593-1601, 1981. S h i r a k i , K., H. Yoshimura, and T. Yamada. Anemia during p h y s i c a l t r a i n i n g and p h y s i c a l performance. In XXth World Congress  i n Sports Medicine Handbook. Melbourne, 1974, pp. 410-415. S i e g e l , A., C. Hennekens, H. Solomin, and B. Vanboeck. E x e r c i s e -r e l a t e d hematuria. F i n d i n g s i n a group of marathon runners. J.A.M.A. 241(4):391-392, 1979. Skikne, B., S. Lynch, D. Borek, and J . Cook. Iron and blood d o n a t i o n . C l i n . Haematol. 13(1): 271-288, 1984. Stewart, J.B., D.A. A h l q u i s t , M c G i l l , D.B., D.M. I l s t r u p , and R.A. Owen. G a s t r o i n t e s t i n a l blood l o s s and anemia i n runners. Ann. I n t . Med. 100:843-845, 1984. Strandberg Pedersen, H. and N. M o r l i n g . Iron s t o r e s i n blood donors evaluated by serum f e r r i t i n . Scand. J . Haematol. 20:70-76, 1978. 36 V e l l a r , O . D . S t u d i e s on swea t l o s s e s o f n u t r i e n t s . S c a n d . J .  C l i n . L a b . I n v e s t . 2 1 : 1 5 7 - 1 6 7 , 1 9 6 8 . V i d n e s , A . and P . K . O p s t a d . Serum f e r r i t i n i n y o u n g men d u r i n g p r o l o n g e d h e a v y p h y s i c a l e x e r c i s e . S c a n d . J . H a e m a t o l . 2 7 : 1 6 5 - 1 7 0 , 1 9 8 1 . W a l t e r s , G . , F . M i l l e r , and M. Worwood. Serum f e r r i t i n c o n c e n t r a t i o n and i r o n s t o r e s i n n o r m a l s u b j e c t s . J _ j _ C l i n .  P a t h . 2 6 : 7 7 0 - 7 7 2 , 1 9 7 3 . W i s h n i t z e r , R . , E . V o r s t , and A . B e r r e b i . Bone marrow i r o n d e p r e s s i o n i n c o m p e t i t i v e d i s t a n c e r u n n e r s . I n t . J . S p o r t s  M e d . 4 ( l ) : 2 7 - 3 0 , 1 9 8 3 . Y o s h i m u r a , H . A n e m i a d u r i n g p h y s i c a l t r a i n i n g ( s p o r t s a n e m i a ) . N u t r . R e v . 2 8 : 2 5 1 - 2 5 3 , 1 9 7 0 . 37 APPENDIX 1 I n i t i a l S c r e e n i n g Q u e s t i o n n a i r e 38 IRON STUDY Name: Phone Number: Subject t Subject 0 PERSONAL DATA Date of Birth: Height: Weight: ACTIVITY LEVEL MENSTRUAL DATA MEDICATIONS Runner Non-runner (£35 miles/week) (< 20 mine, 3 times per week) Birth Control- P i l l IUD Regular Periods- Length Flow- Light Medium Heavy Duration (days)-History of Amenorrhea-N Type: IRON SUPPLEMENTS Y N Dosage:_ BLOOD DONOR KNOWN SOURCE OF BLOOD LOSS Date Started: Last Donation: Y N Red Urine? Black/Red Stool? Other HOLIDAYS Date: Duration: fl Date: Consent Form Dietary Sheets (3-day) Activity Sheets(4) Supplement Sheet Supplements Amount Arrange return v i s i t Contact dates (reminders) #2 Date: Dietary Sheets (3-day) Returned? Supplements No. returned Amount given Arrange return v i s i t Contact dates 03 Date: Dietary Sheets returned-Activity Sheets returned Supplements No. returned Nutrition counselling? Date: BL00DW0RK Date: Serum F e r r i t i n Hemoglobin 3 9 APPENDIX 2 D i e t a r y R e c o r d S h e e t s 40 1 COMPUTERIZED NUTRITION ANALYSIS: Personal Form Y M C A TMi evaluation b only tt accurate at thi Irmxnuutai you provkte on these form. To obtain the best mutts, Mow the Imtructfow carefufly and comptota ALL sections at accurately at possible. Complete: 1. ONE green personal form only. 2. ONE white computer form FOR EACH DAY to be analyzed. SECTION PERSONAL OAR No. OF DAYS TO BE ANALYZED . NAME _ ADDRESS. GROUP. PHONE NUMBER SEX: MALE • FEMALE • HBGHT (without shoes) Inches OR cm WBGHT (without clothes) lbs. OR kg FRAME SIZE: SmaflD Medhmd LargeD BIRTHOATE djy month yotr 00 YOU WISH TO LOSE WEIGHT? YESD NOD ARE YOU ON A SPECIAL DIET? YESD NOD ARE YOU TAKING VITAMIN/MINERAL SUPPLEMENTS? YESD NOD ARE YOU PREGNANT? YESD NOD ARE YOU NURSING? YESD NOD SECTION B: FOOD RECORD 1. Use a worksheet (see sample) to list EVERYTHING YOU ATE OR ORANK for EACH OAY to be analyzed. Be sure to include: a) ALL FOOD AND DRINKS, for example: snacks, sugar and cream in coffee, mayonnaise In a sandwich, sauce on vegetables, candles, soft drinks, wine, etc. b) THE TIME OF OAY these foods were consumed. c) THE AMOUNT OF FOOD that you ate (ounces, slices, cups, teaspoons, etc., in whole or decimal numbers). 2. On the WHITE COMPUTER SHEET, enter the NUMBS) OF SOWINGS of ALL foods and drinks ACCORDING TO USTH) SERVING SIZE. TIME OF OAY? HOW MUCH? FOOD OR DRINK? 10- 1*5 am 11- 00 noon OofffcC octette a) Break dawn al uunibhuUon foods. (For example, cheese omelette in food record above.) b) NOTE THE SERVING SIZE c) WRITE the number of servings you had in the CORRECT TIME SLOT FOODS EATEN ^ Serving Size^. Uj NO ^ •3ERVING9»4 CODE Office Use Only jBam# iiamV 11am-5am MEAT, FBH, EM OR POULTRY EGG 1 2 10129 Cheese: Cheddar 1 oz. I.S 10009 vegetable Oil 1 tbsp. o.s 40518 Program erigtrady developed by Action B.C. Copyrighted 1983. T h b t o n n ^ to reproduce wim the conseirtdtt^ V6Z1Y2 (604)6814221 41 Ye COMPUTERIZED NUTRITION ANALYSIS: Computer Form NAME. DAT£_ GROUP. 05 ACTIVITY: Hours at each level H55S War ' SiMpkt/RwIog " 2 SeUcVSunrJin, _ EVALUATION DAY NUMBER 3 4 „ 5.. Light Acdvby K M T F T -: 24.0Hours F0006 EATEN Scoring SUa NO. OF SERVINGS COOE FOODS EATEN NO. OF SERVINGS COOE Sam-1 1 a m l l a m -Spm Spm* Sam ome Use Only Sffving S i n J a m -i l am 1 1 a m -5pm Som-5am Office UaaOi*/ a u « M mx mooucn FRESH: appal i m d . 1 J CHEESE: n n M M . soft 101 looor apneots (31. mango (S*| 1 w n . 30 cMdar. batd l o t loom banana trnad. 141 oifljtft ctwnc Vi cup 1001S K S o a n 4 T r « E 8 S » M ft cup 1649 CnNJffl CfldOSS l i t 10017 1 cup 663 praoMMd o tUct). iproad (2 (top.) 1 eerv. 10042 papas 1 cup 1065 Swtttorgouda 1 01 10040 grapefruit ft 1053 Vicup tottsi iMtona: tanctfoupa (orange) ft 1356 lea milk Vicup 10164 honoydow (pala groan) 2 " M d g * 1360 kraut bratktul: wtttt wWi t C U P 4046 watermelon W 2424 U L K : cftocotUi 1 cup 10109 onmga, tangerine Ifnad. 1420 condmMd, cwMtvnd. f i r d ttbap. 10085 1 aarv. 1479 Ifbep. 11006 pear 1 1502 Icup 10MS plnaappte H ' s u 1611 t » leap 10070 peons, prunae 1 1641 wfcott, tonwgtntnd leap 10077 atraaroarrtaa Viae 2217 M a n t u a t O u tout DM8): aarloMi I t a M » roouRT: irwllawurarj Soc 1 0 1 2 2 dsns 2 952 pun 602 10116 pnaias 2 1616 MEAOS A M C E M M J Mams H c u p 1646 BISCUITS: UMng prjaoar. scene (J"x1 V. ~) t 410 JUICES {vni.nii.nia-): appaj viaa 27 MEADS: Eufopaan. dart' 1 s k a 4S6 ow Vicup 1068 IrvBOraad, <•»»> lance 4S2 graja*!*; Vtcup 1071 wMM, enrtchtd 1 teca 461 omga Vicup 1437 wtalt wtact wftoto grata 1 aaca 471 plrajepo. Vicap 1619 BUMS. ROLLS: ptMn. tanOofptf 1 1902 prune Vicap 1621 whoit VftlMt 1 tSDS mama C8CALS: eootad. wfciH grain Vicup 1391 COOKEO: asparagiii 4aprs. 4 7 dry. Ibksd. #nrtdwd 1 cup 4005 Caere, green, yaaaw Vtcup 16] dfy, chfwMMl. wholt grain 1 cup 403] boats Vicap 385 dry. sugar coeM Icup 4017 t rac t * leap 404 granott Vicup 4101 tVuiMti tpfouM 6 490 CRACKERS: ( M R 4 010 cabbaga Vicap 511 M t M t o n t 2 4061 carrot! Vicap ( 2 0 . M a c r o 2 stg CMUtoVPtT leap 631 M U F m s : M i Imod. 134S cMnaaa gntn i , bok &&/ leap 520 wftoto gram, b m lined. 1346 tern, kamtl (ft cup), cob (1 n . | 1 aarv. • 5 7 PASTA: i imjiwt, Motfts. ipaghwn 1 cup 1300 aggplant Vicup 997 naCAKES. WFFLES: 4" dum. t 1457 M m ) vaoaUNaa Vicup 2404 FIE CRUST: pufe. Invar crust •adoa 1M6 o w n Vicap 141] DICE: bream Vicap 1670 parsnips Vicup 1474 wMW, mimiwi parboMd vicup 1674 vicup 15X M k , unanrlclMd Vicup 1S76 ****** ^.t*mo.<n**mi Imad. 1766 HISCEUAIIEOUS: DTK vtcup 2446 itancfi k i n , triad potatta* 1 cup 1906 •Mat gam 1toep. 2447 KM*** V i e w 1795 yaast tnaw'a tow. 2476 imad. 2249 mtrri •ptnadi Vicup 2170 CANNED: | M a g ) : amMauot Vicup 29 iQwaffi: wtnlar. <t*km Vtcup 2 2 0 0 apricots Heap 35 umntr , tuccfiM Vicup 2192 C I O T M Vicup 671 iDRhlkMl, bafcad, cmwd V I C U P 2294 In* cocktail Vicup 1 0 2 ] tufntpj V I C U P 2353 peaches Vicap 1463 V i e w 903 peers ni l * 1S07 V i e w 4059 plums, prunes Vi cup 1645 potato, with dnutng Vicup 1612 rhubarb Vi cup 1066 jwcado Vi 6 4 ottiari • chooaa FRESH + 3 tip. sugar oaf swing carrots Imad. 6 1 9 Copyright 1983. This form may be reproduced with the consent ot thi Vancouver. YMCA. 955 Burrard Street. Vancouver. B.C. V6Z 1Y2 (604)681-0221. 8 crtery 1 stalk 6 3 7 cucumDar rsacas 9 4 3 Qraan pappar. dead v« cup 1 5 4 5 42 FOODS EATEN Serving S i n NO. OP SERVINGS , , „ „ . FOODS EATEN I Serving 1 SIM j NO. OF SERVINGS j r f ) n ( 5*m-n am 11 am • 3 pm 5pm • Sam Otlice U M Only Sam • li am 11 am • 5 pm -3 pm 5 am OHica UtaOnty ktttwca. chopped 1 cup int OHHIITS, IWfETS. i w E D e o o o t iivwftraoRtt % cud 1354 Jam. tatty. honey, lyrup IIMp. 1141 OfltoM, 0fM(1 1 141s Mouiaas 11Mp. 1141 radlahaa 2 i e « Sugar: while, brown 1 lap. 2210 aorouta: oaen. tKttU M c W <M Sweet eauce. lopping 2 reap. 781 tana* 1 mad. 2212 CAN0V: dardiei caramelKl) mar»nmi»w»(< t aarv. 80! JUICES: tsnWo. trepatable Vkcup 2268 chaaiingoum ipajca (90 a m . ran. f U M F o v i n r clwcolalobar 1 517 tee t 10129 cnecxaiM 1 594 FOH: C M . M U M . eat: t m d l o t m CA«£: angel tod M d g e 521 • K I M toe 1100 ami ? « m i n 512 1 I Q I ; pyrin, no idng 2M "aq 514 t n M M M r l l K i J u 4089 rich, with Icing I V i " n 526 umon. t t in i .MM6 1 « 1K< COOK ICS: ProMMat. aquarea 1 an C M M d H u p 2124 checolala cNp 1 116 SHELLFISH: ctarae(S|. c f U v M t l 1 U r v m granolauert 2 4101 cnp.kjeaar 3 CI 90S eaanatl 1 4069 ehrtap, eealepe l o t 2045 other, .aeoned 1 812 MEM: beet. « M . p M . M W p g l l i Set 170 Doughnut. Daman pastry, ecu* 1 938 rant l o i 2487 Ftuaemp H o p 25 • M eat 1104 .MMdeaaort.ajIb) H e a p 1032 n a n a l e i sa Pti ( JW* wodgt), M l , tvnnvof 1 1588 W I I K W ( m e t ) l e t ten PapHfU. tots 1 1144 M:fOIK.CMP S a l < t » H e a p • 4 * •wy.uiejl i i i—u ) n 1287 H e a p 1S26 M r pUt l o i <9X rtcs. tapioca Heap 1991 •WICAtMIMIt , CtfMM) l e i 2006 SlMTOM Heap 100M pork: bacon <B*M) lances 126 H V B U a a M M I N t t b a n , btck bacon l o t 1769 ALCOHOL: OMT 12ei » 4 roost, chops (2 smJ) l o t 1717 HQUMTO az\. dotsort winoOvt oi) 1 400 u u t a g n K ' **> i 2014 liquor m e i se sportrt&t enba 17S2 wtnt.ttMt 401 401 wvtnW (lWlMlMl*jr) 1 1991 CarboMMd, pop (non-ttol) 10 u 404 POumr:cMciD>i:raM l e i 50019 Co»m leap 4051 Med l e i soooe Froil Oawurad drink (cryttitt) leap 404] enter: nsaat l e i 5 0 1 « H«cf iocelW<MNtfk) leap 779 •EaMimwia LomoMdo 1 cup 1252 Buns. COMB): Honey, n e H e a p ISO leap 4070 llaa ft cup 177 I M . <« fetid, odd 2 bp. sugar) leap 4050 «"/ H e a p 2140 tftftCTt •MM H e a p 1S5 Cora cMps or MOCkt , C&OOZiM am. pkg. 4080 Lemt* Vicup 1254 Popcorn (wNti o" and son) leap 1695 SpMpoea Vicup 1S33 M a a o w aet. pttg 1809 H U T S : « , « M Heap 1495 •tenant am. pkg 1614 rw u cup 1495 cotaeaunooi pamou Poena! Patau 2 leap. 1499 Baked oaana wati tone** aauoa leap 156 SeedKeetfOOT.eoaarm s o a p . 22M ChMwWiDeane 1 cap 756 Tor. oaen cum 2 at 2145 Chop eeoy wart raaat leap 762 torn. uvea, comaism. oratu Macaroni and cheoae 1 CUP 1104 SOUPS: oraat: ceneuwane, plain 1 cap 2065 MOOflOJt l o t 2007 a r i n n g t a u n leup 2100 MootPM (t smol. 3rt" vMd0t | 1 162 M » M H leup 208/ H a s witti cMoto. lomitp tauco 6''<redga 1828 ehoerow.com (no nark) 1 cup 20*5 SpOQftffll wttft CtWMt, WltMO oVMJOO leap 2181 1 cup 2090 SMw mot wWi w g o U b i M 1 cup 171 heal. W W 1 cup 2097 SAUCES: envy Weep 40S4 BuOsr. IpM l isp . 10001 M i a t i Weep 229S CREAM: c c f l M . 1 pkg. Ilbep. 10049 * • » . « cheese, add Vt OIoajddori H e a p 2470 tour Itoap. 10058 Master* trap. 117] wMppotf Heap 10053 Pickets (2 tacn l . reran (1 tow J 1 1559 •ottoo wMtonor, croani wottttutt Itep. 10069 Soyaauco tttjsp. 2158 Hsrgonno 1 lap. 41110 Tomsk: kacftuo imag. 22H VogoUrtMoi. i tMp 40518 lernrtnetice Itusp. 1245 SALAD (WESSMGS: Wm c h m t 1 reap. 45519 (ranch, on and vnegar Heap. 45120 low u l . diet 1 map. 45021 mayonnaisa 1 rosp. 45018 Thoutand Island t leap. 4S017 4 3 APPENDIX 3 D a i l y M o n i t o r i n g S h e e t 44 SUPPLEMENTATION RECORD SHEET Subject # 1. Supplementation may begin immediately f o l l o w i n g the 3-day d i e t a r y i n t a k e r e c o r d . 2. Take t a b l e t ( s ) b e f o r e bedtime f o r the f i r s t 4 days o f the study. The t a b l e t ( s ) should be taken with j u i c e . (3/4 c.OJ/ 1 c. grapefruit/ 1 c. v i t . apple ) 3. For the remainder of the study, take t a b l e t ( s ) b e f o r e b r e a k f a s t and t a b l e t ( s ) b e f o r e bedtime. Please note t h a t maximal i r o n a b s o r p t i o n occurs on an empty stomach and t h a t c o f f e e and t e a i n h i b i t i r o n a b s o r p t i o n . 4. Use the f o l l o w i n g c h a r t to r e c o r d supplementation by chec k i n g o f f the a p p r o p r i a t e space each, time the supplements are taken. Include any r e l e v a n t comments i n the space p r o v i d e d . MQN. TUBS. WED. THDRS. FRI. SAT. SUN. COMMENTS Week 1 B k f s t Date: Bed Week 2 B k f s t Bed Week 3 B k f s t Bed Week 4 B k f s t Bed Week 5 B k f s t -Bed week 6 B k f s t Bed ** RETURN TO CLINIC BETWEEN WEEK 6-8. BRING IRON PILLS. ARRANGE BLOOD TEST ** Week 7 B k f s t Bed Week 8 B k f s t Bed Week 9 B k f s t Bed Week 10 B k f s t Bed Week 11 B k f s t Bed Week 12 B k f s t Bed ** RETURN TO CLINIC. BRING IRON PILLS. ARRANGE BLOOD TEST AFTER WEEK 12 ** Please r e c o r d as a c c u r a t e l y and h o n e s t l y as p o s s i b l e . Thank youl **Record menstrual p e r i o d s i n the Comment s e c t i o r i . P l ease i n d i c a t e d u r a t i o n (days) and amount of flow (no.of tampons/pads used). 45 APPENDIX 4 P h y s i c a l A c t i v i t y R e c o r d S h e e t 46 ACTIVITY RECORD Subject # 1. Maintain your present a c t i v i t y level throughout the duration of the study. 2. RUNNERS- Weekly mileage must average 5 or more miles/day. Record the duration and mileage of a l l runs. Please also indicate any other a c t i v i t y performed. 3. NON-RUNNERS- Act i v i t y level must not exceed 20 minutes of sustained aerobic exercise, 3 times per week. Record a l l a c t i v i t y performed. 4. Please try to be as e x p l i c i t as possible in the space provided. Include weekly dates. W E E K Monday Tuesday Wednesday Thursday Friday Saturday Sunday W E E K Monday Tuesday Wednesday Thursday Friday Saturday Sunday W E E K Monday Tuesday Wednesday Thursday Friday Saturday Sunday 47 APPENDIX 5 R e v i e w o f L i t e r a t u r e 48 REVIEW OF LITERATURE I . H i s t o r i c a l Review Low hemoglobin and h e m a t o c r i t v a l u e s have been observed f o r more than 30 y e a r s i n h i g h l y t r a i n e d endurance a t h l e t e s ( B e r r y et a l . , 1949; Clement e t a l . , 1977, 1982; Clement and Asmundson, 1982; DeWijn e t a l . , 1971; P a t e , 1983; Stewart e t a l . , 1972). Dewijn e t a l . ( 1 9 7 1 ) r e p o r t e d t h a t 4.5 t o 6% of the a t h l e t e s on the 1968 Dutch Olympic team had hemoglobin v a l u e s i n d i c a t i v e of anemia ( W i n t r o b e , 1981) and a h e m a t o l o g i c a l survey of the 1976 Candadian Olympic team r e v e a l e d hemoglobin v a l u e s below t h a t of the g e n e r a l Canadian p o p u l a t i o n (Clement et a l . , 1977). E x a m i n a t i o n of the members of the 1968 A u s t r a l i a n team r e v e a l e d s i m i l a r f i n d i n g s ( S t e w a r t e t a l . , 1972). A l t h o u g h none were anemic a c c o r d i n g to normal s t a n d a r d s , the A u s t r a l i a n male endurance a t h l e t e s had s i g n i f i c a n t l y lower hemoglobin l e v e l s than a t h l e t e s not i n v o l v e d i n endurance t r a i n i n g . One p o s s i b l e e x p l a n a t i o n f o r t h e s e reduced hemoglobin v a l u e s i s r e l a t e d t o the change i n b l o o d volume t h a t can occur w i t h t r a i n i n g . S e v e r a l i n v e s t i g a t o r s ( B r o t h e r h o o d e t a l . , 1975; D i l l e t a l . , 1974; O s c a i e t a l . , 1968) suggest t h a t t h i s anemia r e p r e s e n t s an a p p a r e n t , r a t h e r than an a b s o l u t e anemia and i s a r e s u l t of an e x e r c i s e - i n d u c e d i n c r e a s e i n t o t a l b lood volume w i t h o u t an e q u i v a l e n t r i s e i n the number of red b l o o d c e l l s . The o c c u r r e n c e of an anemia a s s o c i a t e d w i t h i n t e n s i v e t r a i n i n g has been w e l l documented i n the Japanese l i t e r a t u r e ( Y oshimura, 1970). As a r e s u l t , the term " s p o r t s anemia" was c o i n e d t o d e f i n e the drop i n hemoglobin which o c c u r s as an acute 4 9 response t o e x e r c i s e . The a t h l e t e w i t h s p o r t s anemia e x h i b i t s a subnormal hemoglobin l e v e l i n the absence of any r e c o g n i z e d d i s e a s e p r o c e s s . T h i s has been a t t r i b u t e d to a d e s t r u c t i o n of e r y t h r o c y t e s , and appears to be caused by a s t r e s s r e a c t i o n to s t r e n u o u s muscular e x e r c i s e . Yoshimura (1980) has s p e c u l a t e d t h a t a s p l e e n s e c r e t i o n , l y s o l e c i t h i n , or some o t h e r hemolyzing f a c t o r r e l e a s e d d u r i n g p h y s i c a l e x e r t i o n may i n i t i a t e " s p o r t s anemia". Other i n v e s t i g a t o r s have f u r t h e r s u b s t a n t i a t e d the e x i s t e n c e of " s p o r t s anemia" ( D r e s s e n d o r f e r et a l . , 1985; Fred e r i c k s o n e t a l . , 1983). While consuming adequate d i e t a r y i r o n , 11 o f 15 male r u n n e r s p a r t i c i p a t i n g i n a 20-day road r a c e (17.3 m i l e s / d a y ) e x p e r i e n c e d a s i g n i f i c a n t d e c l i n e i n hemoglobin l e v e l s which was a t t r i b u t e d to i n t r a v a s c u l a r h e m o l y s i s ( D r e s s e n d o r f e r e t a l . , 1985). In c o n t r a s t to " s p o r t s anemia", i r o n d e f i c i e n c y u s u a l l y d e v e l o p s s l o w l y , p r o g r e s s i n g t h rough s e v e r a l s t a g e s b e f o r e t h e r e i s e v i d e n c e of anemia. I f the amount of i r o n l e a v i n g the body exceeds the i r o n i n t a k e , the body w i l l draw on i t s i r o n s t o r e s to c over the i m b a l a n c e . C o n t i n u a t i o n of t h i s imbalance w i l l e v e n t u a l l y l e a d to a d e p l e t i o n of i r o n s t o r e s , i r o n - d e f i c i e n t e r y t h r o p o i e s i s and f i n a l l y , f r a n k anemia ( B o t h w e l l e t a l . , 1979). Hence, a p r o l o n g e d p e r i o d of i r o n d e f i c i e n c y c o u l d a l s o e x p l a i n the anemia obse r v e d i n a t h l e t e s . S e v e r a l r e p o r t s i n the r e c e n t l i t e r a t u r e suggest t h a t a t h l e t e s may be prone to i r o n d e f i c i e n c y (Clement and Asmundson, 1982; Dufaux e t a l . , 1981; Ehn e t a l . , 1980; N i c k e r s o n and T r i p p , 1983; N i c k e r s o n e t a l . , 1985; P a k a r i n e n , 1980; W i s h n i t z e r e t a l . , 1983). Clement and Asmundson (1982) r e p o r t e d t h a t , based on an 50 assessment of body i r o n s t o r e s , 29% of male and 82% of female e l i t e Canadian d i s t a n c e r u n n e r s were i r o n d e f i c i e n t . None of the females were anemic but 10% o f t h e male d i s t a n c e runners had depressed hemoglobin l e v e l s i n d i c a t i v e of anemia. P a k a r i n e n (1980) a l s o observed t h a t a p p r o x i m a t e l y 35% of e l i t e F i n n i s h r u n n e r s showed marked d e p l e t i o n of body i r o n s t o r e s . An i n v e s t i g a t i o n of the i r o n s t a t u s i n 8 e l i t e l o n g d i s t a n c e r u n n e r s showed t h a t , d e s p i t e normal hemoglobin v a l u e s , the bone marrow showed e i t h e r an absence or o n l y t r a c e s of i r o n , i n d i c a t i n g an e a r l y s tage of i r o n d e f i c i e n c y (Ehn et a l . , 1980). More r e c e n t l y , t h i s r e l a t i v e l y h i g h i n c i d e n c e of i r o n d e f i c i e n c y i n a t h l e t e s was c o n f i r m e d by o t h e r i n v e s t i g a t o r s who found t h a t a l a r g e p o r t i o n of a t h l e t e s examined had i n a d e q u a t e i r o n s t o r e s ( N i c k e r s o n and T r i p p , 1983; N i c k e r s o n e t a l . , 1985: W i s h n i t z e r e t a l . , 1983). A g r e a t e r r i s k of i r o n d e f i c i e n c y appeared to be r e l a t e d to h i g h e r t r a i n i n g m i l e a g e s ( N i c k e r s o n et a l . , 1985). F u r t h e r m o r e , i r o n d e f i c i e n c y has been observed i n both e l i t e and r e c r e a t i o n a l r u n n e r s ( C o l t and Heyman, 1984; Hunding et a l . , 1981). In c o n t r a s t , Swedish i n v e s t i g a t o r s (Magnusson et a l . , 1984a, 1984b) have r e c e n t l y c o n t e s t e d the assessment of i r o n d e f i c i e n c y i n a t h l e t e s . A l t h o u g h the r u n n e r s had reduced serum f e r r i t i n v a l u e s and reduced amounts of h e m o s i d e r i n i n bone marrow (Magnusson e t a l . , 1984a), i t was suggested t h a t a s h i f t i n the red c e l l c a t a b o l i s m i n these a t h l e t e s from the r e t i c u l o e n d o t h e l i a l system t o the h e p a t o c y t e s accounted f o r these f i n d i n g s (Magnusson e t a l . , 1984). Thus, th e s e i n v e s t i g a t o r s d i d 51 not b e l i e v e t h a t the a t h l e t e s were t r u l y i r o n d e f i c i e n t and d i s a g r e e d w i t h r o u t i n e i r o n s u p p l e m e n t a t i o n i n a t h l e t e s . I I . M e t a b o l i c Role of I r o n i n E x e r c i s e The h e a l t h y a d u l t has o n l y 3-5 g of t o t a l body i r o n . D e s p i t e these minute q u a n t i t i e s , i r o n i s e s s e n t i a l f o r l i f e . As an i n t e g r a l c o n s t i t u e n t of hemoglobin, myoglobin and s e v e r a l enzymes, i r o n p l a y s a v i t a l r o l e i n the t r a n s p o r t of oxygen and carbon d i o x i d e and i n the p r o c e s s of c e l l u l a r r e s p i r a t i o n ( F a i r b a n k s and B e u t l e r , 1983; Krause and Mahan, 1979. A c c o r d i n g l y , i t i s of p a r t i c u l a r c o n c e r n to a t h l e t e s who s t r i v e f o r maximal e f f i e n c y i n energy p r o d u c t i o n . In the body, 60-70% of the i r o n i s c l a s s i f i e d as e s s e n t i a l or f u n c t i o n a l i r o n , and i s i n c o r p o r a t e d i n t o hemoglobin, myoglobin and c e r t a i n r e s p i r a t o r y enzymes. Hemoglobin i s a s u b s t a n c e c o n t a i n e d i n the r e d b l o o d c e l l which b i n d s oxygen and carbon d i o x i d e f o r t r a n s p o r t to and from the working t i s s u e s . M y o g l o b i n i s the muscle c o u n t e r p a r t of hemoglobin, which b i n d s oxygen f o r s t o r a g e w i t h i n the muscle p r o v i d i n g an i m m e d i a t e l y a v a i l a b l e s ource of oxygen to the muscle. Cytochromes are e l e c t r o n t r a n s p o r t enzymes t h a t c o n t a i n i r o n . Other i r o n - c o n t a i n i n g enzymes which a r e i m p o r t a n t i n r e s p i r a t i o n i n c l u d e c a t a l a s e , p e r o x i d a s e , NADH-, s u c c i n a t e , aldehyde and a l p h a g l y d e r o p h o s p h a t e dehydrogenases, and x a n t h i n e o x i d a s e ( D a l l m a n , 1974). The r e m a i n i n g 30-40% of the t o t a l body i r o n i s c l a s s i f i e d as s t o r a g e i r o n and s e r v e s as a r e s e r v e f o r any i r o n i m b a l a n c e s . I r o n i s s t o r e d as f e r r i t i n and h e m o s i d e r i n i n the l i v e r , bone marrow and s p l e e n (Krause and Mahan, 1979). 52 I l l . F a c t o r s I n f l u e n c i n g Iron D e f i c i e n c y Normally, the body e f f e c t i v e l y conserves i r o n and only small d a i l y amounts are r e q u i r e d to cover the minimal o b l i g a t o r y l o s s e s . The a d u l t male l o s e s about 1 mg of i r o n d a i l y from the u r i n e , s k i n , g a s t r o i n t e s t i n a l t r a c t , sweat and f e c e s . Adult females l o s e more i r o n due to menstrual l o s s e s . Although the average i r o n l o s s a s s o c i a t e d with menstruation i n females amounts to approximately 0.63 mg/day, some females may r e q u i r e up to 1.75 mg/day to cover menstrual l o s s e s (Bureau of N u t r i t i o n , 1983.) In order to maintain the i r o n balance, the amount of i r o n abosrbed from the d i e t must equal the amount l o s t (Conrad and Barton, 1981). S e v e r a l f a c t o r s may j e o p a r d i s e t h i s imbalance and b r i n g about a s t a t e of i r o n d e f i c i e n c y . P a t h o l o g i c a l F a c t o r s Common causes of i r o n d e f i c i e n c y are c o n d i t i o n s i n which an abnormal blood l o s s o c c u r s . These c o n d i t i o n s may r e s u l t i n an acute or c h r o n i c l o s s of blood which, i n t u r n , could lead to diminished i r o n r e s e r v e s and anemia. Regular blood donors o f t e n have depleted i r o n s t o r e s (Milman and Sondergaard, 1984; Pederson and M o r l i n g , 1978; Skikne, et a l . , 1984). A s u b s t a n t i a l i r o n l o s s (approximately 250 mg) occurs at each blood donation and the d a i l y i r o n requirement may i n c r e a s e 3- to 4 - f o l d with a blood donation of only 500 ml four times a year (Bothwell, 1979). Blood l o s s can a l s o occur from the upper g a s t r o i n t e s t i n a l t r a c t and accounts f o r most i n s t a n c e s of i r o n d e f i c i e n c y observed i n a d u l t males and postmenopausal females. A prolonged d a i l y l o s s of only a few m i l l i l i t e r s of blood w i l l i n e v i t a b l y lead to 53 d e p l e t i o n of i r o n s t o r e s and p o s s i b l e anemia ( B o t h w e l l e t a l . , 1979). An i m p o r t a n t c o n s i d e r a t i o n i n women i n t h e i r r e p r o d u c t i v e y e a r s i s r e g u l a r , heavy m e n s t r u a l b l e e d i n g ( B o t h w e l l and C h a r l t o n , 1981). I f the amount of i r o n absorbed from the d i e t i s i n s u f f i c i e n t t o r e p l a c e t h i s l o s s , an i r o n d e f i c i e n t s t a t e w i l l d e v e l o p . E x e r c i s e - r e l a t e d F a c t o r s 1. Inadequate N u t r i t i o n A l t h o u g h the p r e c i s e mechanism i s u n c l e a r , r e s e a r c h on the i r o n s t a t u s of a t h l e t e s has l e d t o s p e c u l a t i o n t h a t a t h l e t e s may have an i n c r e a s e d i r o n r e q u i r e m e n t a s s o c i a t e d w i t h t r a i n i n g ( B o t t i g e r e t a l . , 1971; K i l b o m , 1971; N i c k e r s o n , 1985). Presumably, t h i s a d d i t i o n a l i r o n demand c o u l d be met by i n c r e a s i n g the i r o n c o n t e n t of the d i e t . However, t h e r e i s e v i d e n c e to i n d i c a t e t h a t t h i s i s not e a s i l y a c h i e v e d . N u t r i t i o n a l a n a l y s i s of female d i s t a n c e r u n n e r s r e v e a l e d an average i r o n i n t a k e of 12.5 mg which i s w e l l below the recommended amount of 14 mg (Clement and Asmundson, 1982; Bureau of N u t r i t i o n , 1983). S i n c e the average Western d i e t s u p p l i e s o n l y 5-6 mg of i r o n per 1000 k c a l , i n t a k e s below 2000 k c a l are o f t e n a s s o c i a t e d w i t h i n a d e q u a t e i r o n i n t a k e (Clement and Asmundson, 1982; Clement e t a l . , 1983). I n p a r t i c u l a r , females are a t s p e c i a l r i s k of i r o n d e f i c i e n c y due to an a l r e a d y i n c r e a s e d i r o n r e q u i r e m e n t w i t h m e n s t r u a t i o n ( B o t h w e l l and C h a r l t o n , 1981). F u r t h e r m o r e , a t h l e t e s i n v o l v e d i n s p o r t s which r e q u i r e an u n u s u a l l y low amount of body f a t o f t e n have low c a l o r i c i n t a k e s . As a consequence, the p o t e n t i a l f o r an 54 i n a d e q u a t e i r o n i n t a k e i s i n c r e a s e d , making n u t r i t i o n a l e v a l u a t i o n s of an a t h l e t e ' s d i e t e s s e n t i a l . 2. I n c r e a s e d Hemolysis S e v e r a l s t u d i e s p r o v i d e e v i d e n c e to suggest t h a t r i g o r o u s , p r o l o n g e d e x e r c i s e causes an a c c e l e r a t e d h e m o l y s i s or d e s t r u c t i o n of the red b l o o d c e l l s p o s s i b l y l e a d i n g to an i n c r e a s e d i r o n r e q u i r e m e n t ( D a v i d s o n , 1964; D r e s s e n d o r f e r et a l . , 1985; F r e d e r i c k s o n e t a l . , 1983: Ekblom e t a l . , 1972; Lindemann et a l . , 1978; P u h l and Runyan, 1980; S h i r a k i e t a l . , 1974; Yoshimura, 1970). S i n c e the i r o n l i b e r a t e d d u r i n g r e d b l o o d c e l l t u r n o v e r can be r e u t i l i z e d , a s h o r t e n e d l i f e s p a n of the red b l o o d c e l l does not d i r e c t l y c o n t r i b u t e to i r o n d e f i c i e n c y . However, t h e r e i s o f t e n an i n c r e a s e d amount of u r i n a r y i r o n e x c r e t e d i n h e m o l y t i c s t a t e s (Conrad and B a r t o n , 1981). Davidson (1964) a t t r i b u t e d the i n c r e a s e d h e m o l y s i s to m e c h a n i c a l trauma, s u g g e s t i n g t h a t some ru n n e r s are p r e d i s p o s e d to hemolyze the red b l o o d c e l l i n the c a p i l l a r i e s of t h e i r f e e t . A l t h o u g h the p o t e n t i a l f o r t h i s trauma e x i s t s , i t would appear to have l i m i t e d r e l e v a n c e w i t h the advent of modern r u n n i n g shoes d e s i g n e d s p e c i f i c a l l y f o r shock a b s o r p t i o n ( D i e h l e t a l . , 1982). N e v e r t h e l e s s , s e v e r a l s t u d i e s have found depressed l e v e l s of v a r i o u s b l o o d i n d i c e s f o l l o w i n g heavy e x e r c i s e , which s t r o n g l y suggest a h e m o l y t i c p r o c e s s ( D r e s s e n d o r f e r e t a l . , 1985;Lindemann et a l . , 1978; Magnusson et a l . , 1984a; P u h l and Runyan, 1980; Radomski et a l . , 1980). H e m a t o l o g i c a l parameters examined i n c l u d e d h a p t o g l o b i n , hemoglobin and h e m a t o c r i t . The i n c r e a s e d red b l o o d c e l l d e s t r u c t i o n as a r e s u l t of e x e r c i s e may be 55 a s s o c i a t e d with a weakening of the s t r u c t u r a l i n t e g r i t y of the c e l l membrane p o s s i b l y due to the traumas, of i n c r e a s e d c i r c u l a t o r y r a t e , i n c r e a s e d body temperature, compression of the red blood c e l l s by muscular a c t i v i t y , acute e x e r c i s e a c i d o s i s , or the pressure from bodyweight i n weight-bearing a c t i v i t i e s such as running. E l e v a t e d l e v e l s of catecholamines observed with e x e r c i s e may a l s o i n c r e a s e both the osmotic and mechanical f r a g i l i t y of e r y t h r o c y t e s and the p o t e n t i a l f o r a c c e l e r a t e d d e s t r u c t i o n (Puhl and Runyan, 1980; Yoshimura, 1970). 3. Decreased Iron Absorption Although i r o n a b s o r p t i o n i s normally enhanced i n p r o p o r t i o n to inadequate i r o n s t o r e s ( H e i n r i c h , 1970), t h i s has not been c l e a r l y demonstrated i n i r o n d e f i c i e n t a t h l e t e s . Using r a d i o a c t i v e i r o n to determine i r o n a b s o r p t i o n , Ehn et a l . (1980) found an i r o n a b s o r p t i o n of only 16.4% i n i r o n d e f i c i e n t d i s t a n c e runners as compared to 30% f o r the c o n t r o l s who a l s o had depleted i r o n s t o r e s . A more recent unpublished study of a small group of i r o n d e f i c i e n t , endurance t r a i n e d females supported these r e s u l t s (Clement et a l . , 1983). The average i r o n a b s o r p t i o n was 29% i n these e x e r c i s i n g females. Compared to p r e v i o u s l y reported i r o n a b s o r p t i o n values of g r e a t e r than 70% i n i r o n d e f i c i e n t , non-e x e r c i s i n g females ( H e i n r i c h , 1970; H e i n r i c h et a l . , 1977), these f i n d i n g s suggest the p o s s i b i l i t y of some a b s o r p t i o n d i s t u r b a n c e i n persons engaged i n p h y s i c a l a c t i v i t y . F u r t h e r i n v e s t i g a t i o n i s necessary to understand these o b s e r v a t i o n s . o 56 4. I n c r e a s e d I r o n Loss An i n c r e a s e d l o s s of i r o n w i t h o u t adequate replacement c o u l d a l s o l e a d t o i r o n d e f i c i e n c y . Ehn e t a l . (1980) found t h a t a t h l e t e s appeared to have a f a s t e r e l i m i n a t i o n of r a d i o a c t i v e i r o n from the body when compared to normal s u b j e c t s . F u r thermore, the a b s o r p t i o n v a l u e s observed f o r endurance t r a i n e d females (Clement et a l . , 1983) may have s i m p l y been a r e f l e c t i o n of an i n c r e a s e d e l i m i n a t i o n of the r a d i o a c t i v e i r o n . I t has been s p e c u l a t e d t h a t t h i s f a s t e r e l i m i n a t i o n of i r o n can be a t t r i b u t e d t o p r o f u s e s w e a t i n g , i n c r e a s e d f e c a l l o s s , h e m o g l o b i n u r i a / m y o g l o b i n u r i a or h e m a t u r i a . A l t h o u g h i r o n l o s s v i a sweat i s u s u a l l y c o n s i d e r e d t o be n e g l i g i b l e i n humans, i t appears t h a t extreme s w e a t i n g can s i g n i f i c a n t l y i n c r e a s e i r o n l o s s e s . Assuming sweat l o s s e s i n a t h l e t e s of 1-3 1/hr and a minimum i r o n c o n c e n t r a t i o n i n sweat of 0.1 mg/1, i r o n l o s s e s c o u l d approach 1.0 mg/day i n e x c e p t i o n a l cases of p rolonged e x e r c i s e ( C o l t e t a l . , 1978; 1983; P a u l e v e t a l . , 1983; V e l l a r , 1968). E l e v a t e d f e c a l i r o n e x c r e t i o n which was observed i n e x e r c i s i n g r a t s (Ruckman and Sherman, 1981) was accounted f o r by the p o s s i b i l i t y of an i n c r e a s e d s e c r e t i o n of endogenous i r o n i n the b i l e . R e c e n t l y , g a s t r o i n t e s t i n a l (GI) b l o o d l o s s has been documented i n marathon r u n n e r s (McMahon et a l . , 1984) and a d u l t male and female r u n n e r s ( S t e w a r t e t a l . , 1984). F e c a l hemoglobin l e v e l s i n c r e a s e d i n 20 out of 24 r u n n e r s f o l l o w i n g 10-42 km r a c e s . I n 7 r u n n e r s , t h e s e f e c a l hemoglobin l o s s e s were g r e a t e r than 3 mg of hemoglobin per gram of s t o o l which corresponded to 57 g r e a t e r than 3 ml of blood (approximately 1.5 mg i r o n ) l o s t through the GI t r a c t i n one day (Stewart et al.,,1984). Furthermore, hemolysis or damage to the muscle c e l l w a l l a s s o c i a t e d with e x e r c i s e may r e s u l t i n e x c e s s i v e amounts of f r e e c i r c u l a t i n g hemoglobin and myoglobin which can be excreted i n the u r i n e (Davidson, 1964, 1969; G i l l i g a n , 1943). Another source of u r i n a r y i r o n l o s s , d i s t i n c t from e i t h e r hemoglobinuria or myoglobinuria, i s hematuria ( B l a c k l o c k , 1977, B o i l e a u et a l . , 1980; S i e g e l et a l . , 1979). Whole blood may be r e l e a s e d i n t o the u r i n e f o l l o w i n g p h y s i c a l e x e r t i o n as a r e s u l t of bladder trauma or b l e e d i n g from the kidney p e l v i s . The blood l o s s may occur m i c r o s c o p i c a l l y and remain undetected or i t may appear as g r o s s l y red u r i n e . IV. E f f e c t s of Iron D e f i c i e n c y i n E x e r c i s e Iron D e f i c i e n c y Without Anemia The e f f e c t s of i r o n d e f i c i e n c y without anemia have only r e c e n t l y been e l u c i d a t e d (Dallman et a l . , 1978). P r e v i o u s l y , the major s i g n i f i c a n c e of a m i l d d e f i c i e n c y was thought to be the p r e d i s p o s i t i o n of the i n d i v i d u a l to the development of a more severe anemia. Although t h i s alone has r e l e v a n c e to a t h l e t e s who may have an i n c r e a s e d i r o n requirement, there i s a d d i t i o n a l evidence to suggest that i r o n d e f i c i e n c y without anemia can reduce p h y s i c a l work c a p a c i t y and lead to excess l a c t a t e p r o d u c t i o n ( F i n c h et a l . , 1976, 1979; Schoene et a l . , 1983). As w e l l , s e v e r a l other symptoms a s s o c i a t e d with anemia are o f t e n observed i n i r o n d e f i c i e n t s u b j e c t s i n the absence of a depressed hemoglobin. These i n c l u d e headache, f a t i g u e , heartburn, changes 58 i n a p p e t i t e , vasomotor d i s t u r b a n c e s , muscular cramping, dyspnea and menorrhagia (Conrad and Barton, 1981). Although hemoglobin l e v e l s were adjusted to normal p r i o r to t e s t i n g , i r o n d e f i c i e n t r a t s showed a marked impairment of running a b i l i t y compared to c o n t r o l s . Depressed c o n c e n t r a t i o n s of myoglobin, cytochrome pigments and s p e c i f i c i r o n - c o n t a i n i n g enzymes were noted i n the i r o n d e f i c i e n t r a t s ( F i n c h et a l . , 1976). An e x c e s s i v e p r o d u c t i o n and accumulation of l a c t i c a c i d i n the muscles as a r e s u l t of decreased enzyme a c t i v i t y presumably c o n t r i b u t e d to the muscle d y s f u n c t i o n ( F i n c h et a l . , 1979). Although human s t u d i e s i n t h i s area are l i m i t e d , those a v a i l a b l e support the f i n d i n g s i n animal s t u d i e s . The improvement i n work c a p a c i t y observed f o l l o w i n g supplementation i n both anemic and non-anemic s u b j e c t s could not be t o t a l l y accounted f o r by the r i s e i n hemoglobin (Ohira et a l . , 1979). In another study, i r o n d e f i c i e n t , non-anemic a t h l e t e s showed s i g n i f i c a n t l y lower maximum l a c t a t e l e v e l s f o r a given workload f o l l o w i n g some replacement of t h e i r body i r o n s t o r e s with 10-14 days of i r o n therapy (Schoene et a l . , 1983). Although the i n t e r p r e t a t i o n of these r e s u l t s i s i n c o n c l u s i v e , the evidence suggests that decreased c o n c e n t r a t i o n s of myoglobin and i r o n - c o n t a i n i n g enzymes important i n energy p r o d u c t i o n may account f o r the r e d u c t i o n i n work c a p a c i t y observed i n i r o n d e f i c i e n t s u b j e c t s with normal hemoglobin l e v e l s . Furthermore, r e g a r d l e s s of the mechanism, i t appears t h a t i r o n d e f i c i e n c y without anemia could s u b s t a n t i a l l y reduce an a t h l e t e ' s a b i l i t y to maximize performance and i s c l e a r l y an 59 u n d e s i r a b l e c o n d i t i o n . Iron D e f i c i e n c y With Anemia The consequences of i r o n d e f i c i e n c y with anemia are w e l l documented. S e v e r a l s t u d i e s i n both r a t s and humans have shown a s i g n i f i c a n t c o r r e l a t i o n between the hemoglobin c o n c e n t r a t i o n s and work c a p a c i t y , with some r e s u l t s i n d i c a t i n g that even minor decrements can impair performance (Anderson and Barkve, 1970; Edgerton et a l . , 1972, 1979; Gardner at a l . , 1977; V i t e r i and Torun, 1974). Presumably, t h i s decreased p h y s i c a l work c a p a c i t y i n anemic s u b j e c t s i s mainly due to the l i m i t e d oxygen d e l i v e r y to the musculature. However, low hemoglobin l e v e l s have a l s o been a s s o c i a t e d with c e r t a i n p h y s i o l o g i c a l adjustments which help to m a i ntain the d e l i v e r y of oxygen to the t i s s u e s . These i n c l u d e a l t e r a t i o n s i n the d i s t r u b u t i o n of the c a r d i a c output and i n c r e a s e d l e v e l s of 2,3-diphosphglycerate i n the red blood c e l l s which enhance oxygen r e l e a s e to the t i s s u e s . T h e r e f o r e , when c o n s i d e r i n g the adverse e f f e c t s of i r o n d e f i c i e n c y anemia on work c a p a c i t y , the v a r i o u s iron-dependent metabolic processes that may be compromised at the t i s s u e l e v e l should not be overlooked as c o n t r i b u t o r y f a c t o r s . From the a t h l e t e ' s standpoint, optimal energy r e l e a s e i s o b v i o u s l y i m p o s s i b l e with i n e f f i c i e n t muscle c e l l metabolism compounded by decreased oxygen t r a n s p o r t and, t h e r e f o r e , prompt r e s o l u t i o n of i r o n s t a t u s i s c r i t i c a l . V. Frequency and Sport S p e c i f i c i t y of Iron D e f i c i e n c y Iron d e f i c i e n c y i s one of the most common of the n u t r i t i o n a l d e f i c i e n c i e s , o c c u r r i n g widely throughout the world. According 60 to the N u t r i t i o n Canada Survey (1973), l a r g e numbers of Canadians of a l l ages are a f f e c t e d by i r o n d e f i c i e n c y . Furthermore, i r o n d e f i c i e n c y i s becoming i n c r e a s i n g l y a s s o c i a t e d with those i n v o l v e d i n heavy p h y s i c a l a c t i v i t y . F o l l o w i n g the d e t e c t i o n of an i n d i r e c t assessment of i r o n r e s e r v e s , numerous i n v e s t i g a t o r s have rep o r t e d i r o n d e f i c i e n c y i n a t h l e t e s (Clement and Asmundson, 1982; Dickson et a l . , 1982; D i e h l et a l . , 1982; Dufaux et a l . , 1981; Pakarinen, 1980). S p e c i f i c a l l y , i r o n d e f i c i e n c y i s observed more f r e q u e n t l y i n e x e r c i s i n g females compared to e x e r c i s i n g males (Clement and Asmundson, 1982). T h i s i s probably a t t r i b u t a b l e to inadequate n u t r i t i o n , s i n c e 76% of Canadian women had i r o n i n t a k e s below the recommendation f o r the g e n e r a l p o p u l a t i o n ( N u t r i t i o n Canada, 1973). Furthermore, i n females, a p o t e n t i a l l y i n c r e a s e d i r o n requirement with e x e r c i s e would compound the problem of a g r e a t e r i r o n need due to menstruation. The p o s s i b i l i t y that t h i s c o n d i t i o n may be s p e c i f i c a l l y a s s o c i a t e d with running t r a i n i n g r e c e n t l y became evident (Dickson et a l . , 1982). A group of ultra-marathon runners, competitive over d i s t a n c e s ranging from 56-160 km, showed evidence of s i g n i f i c a n t l y lower i r o n s t o r e s than a group of i n t e r p r o v i n c i a l c l a s s swimmers. Furthermore, p r e l i m i n a r y s t u d i e s i n v o l v i n g r i g o r o u s l y t r a i n i n g swimmers and long d i s t a n c e runners found that the swimmers d i d not e x h i b i t the same degree of i r o n d e f i c i e n c y observed i n the runners (Ehn et a l . , 1977). In a d d i t i o n , when Dufaux et a l . (1981) compared the i r o n s t a t u s of runners, rowers, and c y c l i s t s to n o n - a t h l e t e s , the runners were the only group with i n d i c a t i o n s of i r o n s t o r e s s i g n i f i c a n t l y lower than the non-61 a t h l e t e s . Thus, i t was concluded that middle and long d i s t a n c e runners have a g r e a t e r tendency than other a t h l e t e s to s u f f e r from i r o n d e f i c i e n c y . VI. Diagnosis of Iron D e f i c i e n c y Iron d e f i c i e n c y i s d e f i n e d as the s t a t e i n which the content of i r o n i n the body i s l e s s than normal (Bothwell and C h a r l t o n , 1982; Fairbanks and B e u t l e r , 1983). I t i s commonly d i v i d e d i n t o 3 stages (Bothwell et a l . , 1979; Cook, 1982; H e i n r i c h , 1970). The e a r l i e s t stage i s r e f e r r e d to as p r e l a t e n t i r o n d e f i c i e n c y and i s c h a r a c t e r i z e d by decreased or absent storage i r o n . While other i r o n i n d i c e s , such as t o t a l i r o n - b i n d i n g c a p a c i t y , serum i r o n , percent s a t u r a t i o n or hemoglobin g e n e r a l l y show changes only a f t e r p r o g r e s s i o n to more advanced stages of i r o n d e f i c i e n c y , serum f e r r i t i n i s a s e n s i t i v e monitor of the consumption of storage i r o n which occurs i n p r e l a t e n t i r o n d e f i c i e n c y (Bezwoda et a l . , 1979; C a v i l l , 1982;Jacobs, 1977; Walters et a l . , 1973). In h e a l t h y , normal i n d i v i d u a l s and those with simple i r o n d e f i c i e n c y or i r o n o v e r l o a d , serum f e r r i t i n l e v e l s have been shown to be p r o p o r t i o n a l to the bone marrow i r o n s t o r e s (Jacobs et a l . , 1972). L e v e l s below 15 ng/ml are c o n s i s t e n t l y a s s o c i a t e d with absent or reduced marrow i r o n while values up to 64 ng/ml may s t i l l i n d i c a t e reduced s t o r e s ( H e i n r i c h et a l . , 1977; Milman et a l . , 1983; Sorbie et a l . , 1975). A serum f e r r i t i n c o n c e n t r a t i o n _< 20 ng/ml was very r e l i a b l e i n terms of i d e n t i f y i n g reduced marrow i r o n s t o r e s . The d i a g n o s t i c e f f i c i e n c y was 0.90 with p r e d i c t i v e values of 0.85 f o r a p o s i t i v e t e s t and 0.91 f o r a negative t e s t . In c o n t r a s t , the c l a s s i c a l 62 i r o n i n d i c e s , i n c l u d i n g serum i r o n , serum t r a n s f e r r i n and t r a n s f e r r i n s a t u r a t i o n , were of l i m i t e d value i n d i s c r i m i n a t i n g between healthy s u b j e c t s with d i f f e r e n t l e v e l s of i r o n s t o r e s (Milraan et a l . , 1983). While serum f e r r i t i n i s a r e l i a b l e assessment of body i r o n s t o r e i n i r o n d e f i c i e n t and normal s u b j e c t s , e l e v a t e d serum f e r r i t i n s may occur with acute b a c t e r i a l and v i r a l i n f e c t i o n s ( B i r g e g a r d et a l . , 1978; E l i n et a l . , 1977). Furthermore, there has been some concern t h a t these l e v e l s may a l s o be f a l s e l y e l e v a t e d i n d i s t a n c e runners f o l l o w i n g heavy t r a i n i n g (Dickson et a l . , 1982). At the completion of a 56 km race, four runners had e l e v a t e d serum f e r r i t i n l e v e l s which f e l l s i g n i f i c a n t l y a f t e r a 2 week p e r i o d of r e s t . Based on the average f a l l , i t was suggested that l e v e l s approximately 35% above the value normally taken to i n d i c a t e i r o n d e f i c e n c y may be more r e p r e s e n t a t i v e of i r o n d e f i c i e n c y i n a c t i v e l y t r a i n i n g runners (Dickson et a l . , 1982). S i m i l a r l y , an acute e f f e c t of e x e r c i s e was observed i n cadets p a r t i c i p a t i n g i n a strenuous 5 day ranger course (Vidnes and Opstad, 1981). In c o n t r a s t , serum f e r r i t i n l e v e l s were not a l t e r e d s i g n i f i c a n t l y i n runners f o l l o w i n g a 20-day road race c o v e r i n g d i s t a n c e s of approximately 17 miles/day (Dressendorfer et a l . , 1985). F o l l o w i n g exhaustion of the body i r o n s t o r e s during the f i r s t stage of i r o n d e f i c i e n c y , the i r o n supply to the developing red c e l l i s di m i n i s h e d and i r o n d e f i c i e n t e r y t h r o p o i e s i s o ccurs. T h i s second stage of i r o n d e f i c i e n c y i s known as l a t e n t i r o n d e f i c i e n c y . I t i s c h a r a c t e r i z e d by an in c r e a s e d t o t a l i r o n 63 b i n d i n g c a p a c i t y and reduced serum i r o n and percent s a t u r a t i o n . While the hemoglobin l e v e l may f a l l s l i g h t l y , i t i s s t i l l w i t h i n the normal range. As i n the f i r s t stage, i r o n a b s o r p t i o n i s i n c r e a s e d . The t h i r d stage i s manifest i r o n d e f i c i e n c y or i r o n d e f i c i e n c y anemia. I t i s c h a r a c t e r i z e d by a drop i n hemoglobin. Consequently, the d e t e c t i o n of anemia s i g n a l s an advanced stage of i r o n d e f i c i e n c y and r e p l e t i o n w i l l be prolonged. In order to prevent i r o n d e f i c i e n c y and to ensure prompt i n t e r v e n t i o n i n the e a r l y stages of the development of i r o n d e f i c i e n c y , an a t h l e t e ' s i r o n s t a t u s should be r e g u l a r l y monitored. I d e a l l y , serum f e r r i t i n and hemoglobin l e v e l s should be assessed at l e a s t 2 to 4 times a year and p e r i o d i c a l n u t r i t i o n a l a n a l y ses to determine d i e t a r y i r o n i n t a k e s would be b e n e f i c i a l (Clement, 1981; F r e d e r i c k s o n et a l . , 1983; Pakarinen, 1980). VII. Treatment of Iron D e f i c i e n c y Before any treatment i s undertaken, a p h y s i c i a n presented with an i r o n d e f i c i e n t a t h l e t e must assess the p a t i e n t and r u l e out any i l l n e s s or medical d i s o r d e r . I f a s p o r t s - i n d u c e d cause i s i m p l i c a t e d , n u t r i t i o n a l c o u n s e l l i n g and/or i r o n supplementation may be a p p r o p r i a t e . Routine checks on serum f e r r i t i n and hemoglobin should continue throughout treatment (Clement, 1981). Although there has been some con t r o v e r s y r e g a r d i n g the v a l i d i t y of serum f e r r i t i n assessments during i r o n supplementation (Krause and S t o l e , 1979; Siimes et a l . , 1974), standard treatment of i r o n d e f i c i e n c y anemia with 180 mg 6 4 elemental i r o n per day has been shown to cause an accurate response i n serum f e r r i t i n (Wheby, 1980). 1. Iron N u t r i t i o n D i e t a r y i r o n comes from two main sources, i e . , those c o n t a i n i n g heme i r o n and non-heme i r o n . Foods which c o n t a i n heme i r o n i n c l u d e l i v e r , kidney, h e a r t , lean red meat, p o u l t r y and f i s h : These are the best sources of r e a d i l y absorbed i r o n . On the other hand, the b i o a v a i l a b i l i t y of non-heme i r o n i s markedly i n f l u e n c e d by the composition of the d i e t ( H a l l b e r g , 1981: Monsen et a l . , 1978) D i e t a r y sources of non-heme i r o n i n c l u d e d r i e d peas and beans, nuts , wholegrain and enr i c h e d breads and c e r e a l s , l e a f y v egetables, eggs, d r i e d f r u i t s , dark molasses and wines (Krause and Mahan, 1979; Monsen et a l . , 1978). However, s i n c e the t y p i c a l Western d i e t c o n t a i n s only 5-6 mg of i r o n per 1000 k c a l , i t i s very d i f f i c u l t to recover from an i r o n d e f i c i e n t s t a t e simply by absorbing more i r o n from a n u t r i t i o n a l l y adequate d i e t ( F a i r b a n k s and B e u t l e r , 1983;Schrier, 1981). 2. Iron Supplementation The b a s i c o b j e c t i v e of i r o n therapy i s to r e p a i r the anemia, i f present, and r e s t o r e the body's i r o n r e s e r v e s . Although a d i e t high i n i r o n should provide s u f f i c i e n t i r o n to maintain adequate s t o r e s , i t i s very d i f f i c u l t to r e p l e t e an i r o n d e f i c i e n t i n d i v i d u a l throught m o d i f i c a t i o n s i n d i e t alone and supplementation must o f t e n be c o n s i d e r e d . Furthermore, a response to i r o n replacement i s co n s i d e r e d d i a g n o s t i c of i r o n d e f i c i e n c y (Bothwell et a l . , 1979; Fairbanks and B e u t l e r , 1983). 65 O r a l Iron Therapy O r a l i r o n therapy g e n e r a l l y c o n s i s t s of approximately 120-200 mg elemental i r o n per day administered as a f e r r o u s s a l t . (Bothwell et a l . , 1979; C a l l e n d e r , 1982; Nimeh and Bishop, 1980).). A s m a l l i n i t i a l dose, g r a d u a l l y i n c r e a s e d to the above l e v e l can minimize g a s t r o i n t e s t i n a l d isturbance from these i r o n s a l t s . The supplement i s p r e f e r a b l y taken on an empty stomach s i n c e the concurrent i n g e s t i o n of food reduces the a v a i l a b i l i t y of i r o n s a l t s . However, a s c o r b i c a c i d , taken c o n c u r r e n t l y i n amounts g r e a t e r than 75 mg, s i g n i f i c a n t l y enhances i r o n a b s o r p t i o n (Monsen et a l . , 1978). Ferrous sulphate, fumarate, gluconate, l a c t a t e , glutamate, s u c c i n a t e and g l y c i n e sulphate are a l l a c c e p t a b l e i r o n s a l t s f o r o r a l therapy (Bothwell et a l . , 1979, C a l l e n d e r , 1982). A s i g n i f i c a n t hemoglobin i n c r e a s e i n anemic i n d i v i d u a l s can be expected f o l l o w i n g 3-4 weeks of i r o n therapy and normal values should be e v i d e n t w i t h i n 2 months. Stores r e p l e n i s h slowly and i t i s o f t e n necessary to continue therapy f o r 2-12 months a f t e r c o r r e c t i o n of anemia to adequately r e p l e t e s t o r e s (Bentley and Jacobs, 1975; Fairbanks and B e u t l e r , 1983). Intramuscular Iron Therapy Intramuscular i r o n supplementation i s r a r e l y used but i t can l e a d to r a p i d replenishment of bone marrow i r o n . Iron dextran i s given i n 2 ml doses 10-14 times per month. Intramuscular i r o n therapy i s more expensive than the o r a l route and c a r r i e s the r i s k of a s e r i o u s a l l e r g i c response ( a n a p h y l a c t i c shock) which 66 can be f a t a l (Bothwell et a l . , 1979; Clement, 1981). J Despite the prevalence of i r o n d e f i c i e n c y i n a t h l e t e s , there i s s t i l l a l a c k of documentation re g a r d i n g the a d m i n i s t r a t i o n of supplemental i r o n f o r the treatment or preve n t i o n of t h i s c o n d i t i o n . T h e r e f o r e , i r o n supplements should not be given r o u t i n e l y to a t h l e t e s without medical s u p e r v i s i o n . In a d d i t i o n to the p o s s i b i l i t y of i n d u c i n g d e f i c i e n c i e s of other t r a c e m i n e r a l s , such as copper and z i n c (Solomons, 1983), a high i r o n i n t a k e can produce an i r o n overload i n some people. T h i s c o n d i t i o n , known as hemochromatosis, i s c h a r a c t e r i z e d by i r o n being deposited i n the l i v e r , j o i n t s , gonads, pancreas, heart and s k i n (Clement, 1981; S c h r i e r , 1981). Hemochromatosis i s much more common than p r e v i o u s l y recognized and recent s t a t i s t i c s i n d i c a t e an i n c i d e n c e i n Canada of approximately 0.3 % (1/333) while almost 11% c a r r y the hemochromatosis gene (Borwein et a l . , 1983). V I I I . Summary E p i d e m i o l o g i c a l s t u d i e s of the i r o n s t a t u s of a t h l e t e s i n v o l v e d i n heavy t r a i n i n g have suggested t h a t these a t h l e t e s may be prone to i r o n d e f i c i e n c y . Based on serum f e r r i t i n l e v e l s which a c c u r a t e l y r e f l e c t the s i z e of the body's i r o n s t o r e s , a high prevalence of i r o n d e f i c i e n c y among a t h l e t e s , p a r t i c u l a r l y endurance runners, has been observed. T h i s c o n d i t i o n i s d i s t i n c t from " s p o r t s anemia" which r e f e r s to the drop i n hemoglobin that occurs as an acute response to e x e r c i s e . Whether i r o n d e f i c i e n c y i n a t h l e t e s i s due to an inadequate 67 d i e t a r y i n t a k e , an e x e r c i s e e f f e c t on i r o n metabolism or a combination of both has yet to be c l e a r l y determined. Regardless of the cause, i r o n d e f i c i e n c y with or without anemia i s an u n d e s i r a b l e c o n d i t i o n f o r an a t h l e t e s t r i v i n g to a t t a i n peak performance a b i l i t y . Regular monitoring of the i r o n s t a t u s of a t h l e t e s i s s t r o n g l y recommended. I f an i r o n d e f i c i e n t c o n d i t i o n i s d e t e c t e d , prompt i n t e r v e n t i o n i n v o l v i n g n u t r i t i o n a l c o u n s e l l i n g and/or i r o n supplementation i s necessary. 68 REFERENCES Andersen, H.T. and H. Barkve. I r o n d e f i c i e n c y and muscular work performance. Scand. J . C l i n . Lab. I n v e s t . 114(Suppl.) 25: 1-62, 1970. B e n t l e y , D.P. and A. J a c o b s . A c c u m u l a t i o n of s t o r a g e i r o n i n p a t i e n t s t r e a t e d f o r i r o n - d e f i c i e n c y anaemia. B r . Med. J . 2:64-66, 1975. B e r r y , W., J . B e v e r i d g e , E. Bransby, A. Chalmers, B. Needham, H. Magee, H. Townsend, and C. Daubney. The d i e t , haemoglobin v a l u e s and b l o o d p r e s s u r e s of Olympic a t h l e t e s . B r . Med. J . 1:300-304, 1949. Bezwoda, W., T. B o t h w e l l , J . T o r r a n c e , A. M a c P h a i l , R. C h a r l t o n , G. Kay, and J . L e v i n . The r e l a t i o n s h i p between marrow i r o n s t o r e s , plasma f e r r i t i n c o n c e n t r a t i o n s and i r o n a b s o r p t i o n . Scand. J . Haematol. 22:113-120, 1979. B i r g e g a r d , G., R. H a l l g r e n , A. K i l l a n d e r , A. Stromberg, P. Venge, and L. Wide. Serum f e r r i t i n d u r i n g i n f e c t i o n . Scand. J .  Haematol. 21:333-340, 1978. B l a c k l o c k , N. B l a d d e r trauma i n the l o n g d i s t a n c e r u n n e r : "10,000 metres h a e m a t u r i a " . B r i t . J . U r o l . 49:129-132, 1977. B o i l e a u , M., E. Fuchs, J . B a r r y , and C. Hodges. S t r e s s h e m a t u r i a : a t h l e t i c p s e u d o n e p h r i t i s i n marathoners. Ur o l o g y 15(5):417-474, 1980. B o r w e i n , S.T., C.N. Ghent, P.R. F l a n a g a n , M.J. C h a m b e r l a i n , and L.S. V a l b e r g . G e n e t i c and p h e n o t y p i c e x p r e s s i o n of hemochromatosis i n C a n a d i a n s . C l i n . I n v e s t . Med. 6:171-179, 1983. B o t h w e l l , T.H. T o t a l i r o n l o s s and r e l a t i v e importance of d i f f e r e n t s o u r c e s . In H a l l b e r g , L., H.G. Harwerth, and A. V a n e t t i ( E d s ) . I r o n D e f i c i e n c y : P a t h o g e n e s i s , C l i n i c a l  A s p e c t s , Therapy. New Y ork, Academic P r e s s , 1970, pp.151-162. B o t h w e l l , T.H. and R. C h a r l t o n . I r o n D e f i c i e n c y i n Women- A^  R e port of the I n t e r n a t i o n a l N u t r i t i o n a l Anaemia C o n s u l t a t i v e  Group (INACG). A p r i l , 1981, pp. 1-57. B o t h w e l l , T.H., R.W. C h a r l t o n , J.D. Cook, and C A . F i n c h . I r o n  M e t a b o l i s m i n Man. O x f o r d , B l a c k w e l l S c i e n t i f i c P u b l i c a t i o n s , 1979, pp. 1-81. B o t t i g e r , L.E., A. Nyberg, I . A s t r a n d , and P-0 A s t r a n d . I r o n a d m i n i s t r a t i o n to h e a l t h y , p h y s i c a l l y very a c t i v e s t u d e n t s . Nord. Med. 85:396-398, 1971. 69 Brotherhood, J . , B. B r o z o v i c , and L.G.C. Pugh. Haematological s t a t u s middle and l o n g - d i s t a n c e runners. C l i n . S c i . Mol.  Med. 48:139-145, 1975. Bureau of N u t r i t i o n Research. Recommended N u t r i e n t Intakes f o r Canadians (4th Ed). Ottawa, Health and Welfare Canada, 1983. C a l l e n d e r , S. Treatment of i r o n d e f i c i e n c y . C l i n . Haematol. 11(2):327-338, 1982. Campbell, M.L. and K.L. MacFayden. N u t r i t i o n knowledge, b e l i e f s and d i e t a r y p r a c t i c e s of c o m p e t i t i v e swimmers. Can. Home Ec. J . 34(l):47-52, 1984. C a v i l l , I . D i a g n o s t i c methods. C l i n . Haematol. 11(2):259-272, 1982. C h a r l t o n , R.W. and T.H. B o t h w e l l . Iron a b s o r p t i o n . Ann. Rev.  Med. 34:55-68, 1983. Clement, D.B. Anemia and i r o n d e f i c i e n c y i n a t h l e t e s . Sports  Science P e r i o d i c a l on Research and Technology i n Sport. November, 1981. Clement, D.B. and R.C. Asmundson. N u t r i t i o n a l i n t a k e and h e m a t o l o g i c a l parameters i n endurance runners. Phys.  Sportsmed. 10(3):37-43, 1982. Clement, D.B., R.C. Asmundson, and C.W. Medhurst. Hemoglobin v a l u e s : comparative survey of the 1976 Canadian Olympic team. Can. Med. Assoc. J . 117:614-616, 1977. Clement, D.B., J.E. Taunton, and K. P o s k i t t . Iron d e f i c i e n c y anemia i n a d i s t a n c e runner. Can. Fam. Phys. 28:1008— 1010, 1982. Clement, D.B., J.E. Taunton, D. McKenzie, D. L y s t e r , L. Sawchuk, and J.P. Wiley. Iron a b s o r p t i o n i n i r o n d e f i c i e n t , endurance t r a i n e d females. Unpublished, 1983. Clement, D.B., J.E. Taunton, D. McKenzie, L.L Sawchuk, and J.P. Wiley. High- and low-dosage i r o n supplementation i n i r o n d e f i c i e n t , endurance t r a i n e d females. In Katch, F. ( E d ) . Sport, H e a l t h , and N u t r i t i o n . Champaign, Human K i n e t i c s P u b l i s h e r s , 1985. C o l t , E. and B. Heyman. Low f e r r i t i n l e v e l s i n runners. J .  Spo r t s Med. 24:13-17, 1984. Conrad, M.E. and J.C. Barton. F a c t o r s a f f e c t i n g i r o n balance. Am. J . Hematol. 10(2):199-225, 1981. 70 Cook, J . C l i n i c a l e v a l u a t i o n of i r o n d e f i c i e n c y . Semin.  Hemat. 19(1):6-18, 1982. Dallman, P. T i s s u e e f f e c t s of i r o n d e f i c i e n c y . In Jacobs, A. and M. Worwood (Eds ) . Iron i n B i o c h e m i s t r y and Medicine. New York, Academic Press, 1974, pp. 437-475. Dallman, P., E. B e u t l e r , C A . F i n c h . E f f e c t s of i r o n d e f i c i e n c y e x c l u s i v e of anaemia. Br. J . Haematol. 40:179-184, 1978. Davidson, R.J.L. E x e r t i o n a l haemoglobinuria: a r e p o r t on three cases with s t u d i e s on the haemolytic mechanism. J ^ C l i n .  Path. 17:536-540, 1964. Davidson, R.J.L. March or e x e r t i o n a l haemoglobinuria. Semin.  Hematol. 6:150-161, 1969. Dacie, J . and S. Lewis. P r a c t i c a l Haematology,5th ed. New York, C h u r c h i l l L i v i n g s t o n e , 1975, pp. 10-20. DeWijn, J.F., J.L. deJongste, W. Mosterd, and D. W i l l e b r a n d . Hemoglobin, packed c e l l volume, serum i r o n and i r o n b i n d i n g c a p a c i t y of s e l e c t e d a t h l e t e s d u r i n g t r a i n i n g . Nutr. Metab. 13:129-139, 1971. Dickson, D.H., R.L. W i l k i n s o n , and T.D. Noakes. E f f e c t s of ultra-marathon t r a i n i n g and r a c i n g on hematologic parameters and serum f e r r i t i n l e v e l s i n w e l l - t r a i n e d a t h l e t e s . I n t . J .  Sports Med. 3(2):111-117, 1982. D i e h l , L., W. B u t l e r , E. Ferguson, and E. Schoomaker. I n t r a v a s c u l a r hemolysis i n marathon runners. C l i n . Res. 30:314, 1982. D i e h l , D., T. Lohman, S. Smith, and R. K e r t z e r . The e f f e c t s of p h y s i c a l t r a i n i n g on the i r o n s t a t u s of female a t h l e t e s . Med. S c i . Sports Exer. 14:164, 1982. D i l l , D.B., K. B r a i t h w a i t e , W.C. Adams, and E.M. Bernauer. Blood volume of m i d d l e - d i s t a n c e runners: e f f e c t of 2,300m a l t i t u d e and comparison with n o n - a t h l e t e s . Med. S c i . S p o r t s . 6 ( l ) : l - 7 , 1974. Dixon, W.J. (Ed) BMDP- S t a t i s t i c a l Software Los Angeles, U n i v e r s i t y of C a l i f o r n i a P r e s s , 1981, pp. 359-387. Dressendorf er, R.H., E.W. Askew, J.E. Rimar, C L . Keen, C E . Wade, S. Gordon, and G.C. Timmis. Development of s p o r t s anemia i n without i r o n d e f i c i e n c y . Med. S c i . Sports 17(2):201, 1985. 71 Dufaux, B. t A. Hoederath, I . S t r e i t b e r g e r , W. Hollman, and G. Assman. Serum f e r r i t i n , t r a n s f e r r i n , h a p t o g l o b i n and i r o n i n m i d d l e - and l o n g - d i s t a n c e r u n n e r s , e l i t e rowers and p r o f e s s i o n a l r a c i n g c y c l i s t s . I n t . J . S p o r t s Med. 2 ( 1 ) : 4 3 -46, 1981. E d g e r t o n , V.R., S.L. B r y a n t , C A . G i l l e s p i e , and G.W. Gardner. I r o n d e f i c i e n c y anemia and p h y s i c a l performance and a c t i v i t y of r a t s . J . N u t r . 102:381-400, 1972. E d g e r t o n , V.R., G.W. Gardner, Y. O h i r a , K.A. Gunawardma, and B. S e n e w i r a t n e . I r o n - d e f i c i e n c y anaemia and i t s e f f e c t on worker p r o d u c t i v i t y and a c t i v i t y p a t t e r n s . Br. Med. J . 2:1546-1549, 1979. Ehn, L., B. C a r l m a r k , and S. Hoglund. I r o n i n young sportsmen. In E r i k s s o n , B. and B. F u r b e r g ( E d s ) . Swimming M e d i c i n e IV. B a l t i m o r e , U n i v e r s i t y Park P r e s s , 1977, pp. 85-88. Ehn, L., B. C a r l m a r k , and S. Hoglund. I r o n s t a t u s i n a t h l e t e s i n v o l v e d i n i n t e n s e p h y s i c a l a c t i v i t y . Med. S c i . S p o r t s  E x e r . 1 2 ( l ) : 6 1 - 6 4 , 1980. Ekblom, B., A. G o l d b a r g , and B. G u l l b r i n g . Response to e x e r c i s e a f t e r b l o o d l o s s and r e i n f u s i o n . J_j_ A p p l . P h y s i o l . 33:175-180, 1972. E l i n , R., S. W o l f f , and C. F i n c h . E f f e c t of induced f e v e r on serum i r o n and f e r r i t i n c o n c e n t r a t i o n s i n man. Blood 49(1):147-153, 1977. F a i r b a n k s , V. and E. B e u t l e r . I r o n d e f i c i e n c y . In W i l l i a m s , W., E. B e u t l e r , A. E r s l e v , and M. L ichtman (Eds) Hematology,  3rd ed. New York, M c G r a w - H i l l Book Company, 1983, pp. 466-484. F i n c h , C.A., L.R. M i l l e r , A.R. Inamdar, R. P e r s o n , K. S e i l e r , and B. M a c k l e r . I r o n d e f i c i e n c y i n the r a t - p h y s i o l o g i c a l and b i o m e c h a n i c a l s t u d i e s o f muscle d y s f u n c t i o n . J . C l i n .  I n v e s t . 58:447-453, 1976. F i n c h , C.A., P.D. G o l l n i c k , M.P. H l a s t a l a , L.R. M i l l a r , E. D i l l m a n , and B. M a c k l e r . L a c t i c a c i d o s i s as a r e s u l t of i r o n d e f i c i e n c y . J_j_ C l i n . I n v e s t . 64:129-137, 1979. F r e d e r i c k s o n , L.A., J . L . P u h l , and W.S. Runyan. E f f e c t s of t r a i n i n g on i n d i c e s of i r o n s t a t u s of young female c r o s s -c o u n t r y r u n n e r s . Med. S c i . S p o r t s E x e r c . 15(4):271-276, . 1983. Gardner, C , V.R. E d g e r t o n , B. S e n e w i r a t n e , R. B a r n a r d , and Y i O h i r a . P h y s i c a l work c a p a c i t y and m e t a b o l i c s t r e s s i n s u b j e c t s w i t h i r o n d e f i c i e n c y anemia. Am. J . C l i n . N u t r . 30:910-917, 1977. 72 G i l l i g a n , D.R., M.D. A l t s c h u l e , and E.M. Katersky. P h y s i o l o g i c i n t r a v a s c u l a r hemolysis of e x e r c i s e . Hemoglobinemia and hemoglobinuria f o l l o w i n g c r o s s - c o u n t r y runs. J . C l i n .  I n v e s t . 22:859, 1943. H a l l b e r g , L. B i o a v a i l a b i l i t y of d i e t a r y i r o n i n man. Ann. Rev. Nutr. 1:123-147, 1981. Hayashi, M., T. Kume, and H. N i h i r a . A b n o r m a l i t i e s of r e n a l venous system and unexplained r e n a l haematuria. J_y_ U r o l . 124:12-16, 1980. H e i n r i c h , H.C. I n t e s t i n a l i r o n a b s o r p t i o n i n man- methods of measurement, dose r e l a t i o n s h i p , d i a g n o s t i c and t h e r a p e u t i c a p p l i c a t i o n s . In H a l l b e r g , L., H.G. Harwerth, and A. V a n e t t i ( E d s ) . Iron D e f i c i e n c y : Pathogenesis, C l i n i c a l  A spects, Therapy. New York, Academic Press, 1970, pp. 213-296. H e i n r i c h , H.C., J . Bruggemann, E.E. Gabbe and M. G l a s e r . C o r r e l a t i o n between d i a g n o s t i c 59 Fe 2+ - a b s o r p t i o n and serum f e r r i t i n c o n c e n t r a t i o n i n man. Z. N a t u r f o r s c h . 32(c):1023-1024, 1977. Hunding, A., R. J o r d a l , and P.Paulev. Runner's anemia and i r o n d e f i c i e n c y . Acta Med. Scand. 209:315-318, 1981. Jacob, R., H. Sandstead, L. Klevay, and L. Johnson. U t i l i t y of serum f e r r i t i n as a measure of i r o n d e f i c i e n c y i n normal males undergoing r e p e t i t i v e phlebotomy. Blood 56:786-791, 1980. Jacobs, A. Serum f e r r i t i n and i r o n s t o r e s . Fed. Proc. 36(7):2024-2027, 1977. Jacobs. A., E. M i l l e r , M. Worwood, M.R. Beamish, and C A . Wardrop. F e r r i t i n i n the serum of normal s u b j e c t s and p a t i e n t s with i r o n d e f i c i e n c y and i r o n o v e r l o a d . Br. Med.  J . 4:206-208, 1972. Kilbom. A. P h y s i c a l t r a i n i n g with submaximal i n t e n s i t i e s i n women: r e a c t i o n to e x e r c i s e and o r t h o s t a s i s . Scand. J .  C l i n . Lab. In v e s t . 28:141-161, 1971. Krause, J . and S t o l e , V. Serum f e r r i t i n and bone marrow i r o n s t o r e s . I. C o r r e l a t i o n with absence of i r o n i n biopsy specimens. Am. J . C l i n . P a t h o l . 72:817-820, 1979. Krause, M. and L. Mahan. Food, N u t r i t i o n and Di e t Therapy. P h i l a d e l p h i a , W.B. Saunders Company, 1979, pp. 129-135. Lindemann, R., R. Ekanger, P.K. Opstad, M. Nummestad, and R. L j o s l a n d . Hematological changes i n normal men du r i n g prolonged severe e x e r c i s e . Am. C o r r e c t . Ther. J . 32(4):107-111, 1978. 73 Magnusson, B., L. H a l l b e r g , L. Rossander, and B., S w o l i n . I r o n m etabolism and " s p o r t s anemia". I . A study of s e v e r a l i r o n parameters i n e l i t e r u n n e r s w i t h d i f f e r e n c e s i n i r o n s t a t u s . A c t a Med. Scand. 216:149-155, 1984a. Magnusson, B., L. H a l l b e r g , L. Rossander, and B. S w o l i n . I r o n m e t abolism and " s p o r t s anemia". I I . A h e m a t o l o g i c a l comparison of e l i t e r u n n e r s and c o n t r o l s u b j e c t s . A c t a Med.  Scand. 216:157-164, 1984b. McMahon, L.F., M.J. Ryan, D. L a r s o n , R.L. F i s h e r . O c c u l t g a s t r o i n t e s t i n a l b l o o d l o s s i n marathon r u n n e r s . Ann. I n t .  Med. 100:846-847, 1984. Milman, N. and M. Sondergaard. I r o n s t o r e s i n male b l o o d donors e v a l u a t e d by serum f e r r i t i n . T r a n s f u s i o n 24:464-468, 1984. Milman, N., N. S t r a n d b e r g P e d e r s e n , V i s f e l d t , J . Serum f e r r i t i n i n h e a l t h y Danes: r e l a t i o n t o marrow h a e m o s i d e r i n i r o n s t o r e s . Dan. Med. B u l l . 30:115-120, 1983. Monsen, E., L. H a l l b e r g , J . L a y r i s s e , D. Hegsted, J . Cook, W. M e r t z , and C. F i n c h . E s t i m a t i o n of a v a i l a b l e d i e t a r y i r o n . Am. J . C l i n . N u t r . 31:134-141, 1978. N i c k e r s o n , H.J. and A. T r i p p . I r o n d e f i c i e n c y i n a d o l e s c e n t c r o s s - c o u n t r y r u n n e r s . Phys. Sportsmed. l l ( 6 ) : 6 0 - 6 6 , 1983. N i c k e r s o n , H.J., M. H o l u b e t s , A. T r i p p , and W. P i e r c e . Decreased i r o n s t o r e s i n h i g h s c h o o l female r u n n e r s . Am. J . C h i l d .  D i s e a s e s . A ccepted f o r p u b l i c a t i o n , 1985. Nimeh, N. and R.C. B i s h o p . D i s o r d e r s of i r o n m etabolism. Med•  C l i n . N. Amer. 64(4):631-645, 1980. N u t r i t i o n Canada. N u t r i t i o n - A_ N a t i o n a l P r i o r i t y . Ottawa, I n f o r m a t i o n Canada, 1973. O h i r a , Y., V.R. E d g e r t o n , G.W. Gardner, B. S e n e w i r a t n e , R.J. B a r n a r d , and D.R. Simpson. Work c a p a c i t y , h e a r t r a t e and b l o o d l a c t a t e r e s p o n s e s t o i r o n t r e a t m e n t . B r i t . J .  Haemotol. 41:365-372, 1979. O s c a i , L.B., B.T. W i l l i a m s , and B.A. H e r t i g . E f f e c t of e x e r c i s e on b l o o d volume. J . A p p l . P h y s i o l . 24(5):622-624, 1968. P a k a r i n e n , A. F e r r i t i n i n s p o r t m e d i c i n e . N o r d i c l a b - N e w s l e t t e r s 4:20-28, 1980. P a t e , R. S p o r t s anemia: a r e v i e w of the c u r r e n t r e s e a r c h l i t e r a t u r e . Phys. Sportsmed. 11(2):115-131, 1983. 74 Paulev, P., R. J o r d a l , and N. Pedersen. Dermal e x c r e t i o n of i r o n i n i n t e n s e l y t r a i n i n g a t h l e t e s . C l i n . Chem. Acta 127:19-27, 1983. Puhl, J.L. and W.S. Runyan. Hematological v a r i a t i o n s during a e r o b i c t r a i n i n g of c o l l e g e women. Res. Quart. Exer. Sport 51(3):533-541, 1980. Radomski, M.W., B.H. S a b i s t o n , and P. Is o a r d . Development of " s p o r t s anemia" i n p h y s i c a l l y f i t men a f t e r d a i l y s u s t a i n e d sub-maximal e x e r c i s e . A v i a t . Space E n v i r o n . Med. 51:41-45, 1980. Ruckman, K. and A. Sherman. E f f e c t s of e x e r c i s e on i r o n and copper metabolism i n r a t s . J . Nutr. 111:1593-1601, 1981. Schoene, R., P. Escourrou, H. Robertson, K. N i l s o n , J . Parsons, and N. Smith. Iron r e p l e t i o n decreases maximal e x e r c i s e l a c t a t e c o n c e n t r a t i o n s i n female a t h l e t e s with minimal i r o n d e f i c i e n c y anemia. J . Lab. C l i n . Med. 102(2):306-312, 1983. S c h r i e r , S. Anemia: blood l o s s and d i s o r d e r s of i r o n metabolism. In Rubenstein, E. and D. Federman ( E d s ) . S c i e n t i f i c  American Medicine• New York, S c i e n t i f i c American Inc., 1981, pp. 1-12. S h i r a k i , K., H. Yoshimura, and T. Yamada. Anemia during p h y s i c a l t r a i n i n g and p h y s i c a l performance. In XXth World Congress  i n Sports Medicine Handbook. Melbourne, 1974, pp. 410-415. S i e g e l , A., C. Hennekens, H. Solomin, and B. Vanboeck. E x e r c i s e -r e l a t e d hematuria. F i n d i n g s i n a group of marathon runners. J.A.M.A. 241(4):391-392, 1979. Siimes, M.A., J.E. Addiego,Jr., and P.R. Dallman. F e r r i t i n i n serum: d i a g n o s i s of i r o n d e f i c i e n c y and i r o n overload i n i n f a n t s and c h i l d r e n . Blood 43:581, 1974. Skikne, B., S. Lynch, D. Borek, and J . Cook. Iron and blood donation. C l i n . Haematol. 13(1):271-288, 1984. Solomons, N. M i n e r a l i n t e r a c t i o n s i n the d i e t . Nutr. Today 38(5):603-606, 1983. Sor b i e , J . , L.S. Val b e r g , W.E. C o r b e t t , and J . Ludwig. Serum f e r r i t i n , c o b a l t e x c r e t i o n and body i r o n s t a t u s . Can. Med.  Assoc. J . 112:1173-1178, 1975. Stewart, G.A., J.E. S t e e l , M.B. Tayne, and M.H. Stewart. Observations on the haematology and the i r o n and p r o t e i n i n t a k e of A u s t r a l i a n Olympic a t h l e t e s . Med. J . Aust. 2:1339-1342, 1972. 75 Stewart, J.B., D.A. A h l q u i s t , M c G i l l , D.B., D.M. I l s t r u p , and R.A. Owen. G a s t r o i n t e s t i n a l blood l o s s and anemia i n runners. Ann. I n t . Med. 100:843-845, 1984. Strandberg Pedersen, H. and N. M o r l i n g . Iron s t o r e s i n blood donors evaluated by serum f e r r i t i n . Scand. J . Haematol. 20:70-76, 1978. Torrance, J . , P. Jacobs, A. Restrepo, J . Eschbach, C. Lenfant, and C. F i n c h . I n t r a e r y t h r o c y t i c a d a p t a t i o n to anemia. New  Eng. J . Med. 283:165-169, 1970. V e l l a r , O.D. Studies on sweat l o s s e s of n u t r i e n t s . Scand. J .  C l i n . Lab. In v e s t . 21:157-167, 1968. Vidnes, A. and P.K. Opstad. Serum f e r r i t i n i n young men during prolonged heavy p h y s i c a l e x e r c i s e . Scand. J . Haematol. 27:165-170, 1981. V i t e r i , R. and B. Torun. Anemia and p h y s i c a l work c a p a c i t y . C l i n . Haematol. 3:609-626, 1974. Walters, G., F. M i l l e r , and M. Worwood. Serum f e r r i t i n c o n c e n t r a t i o n and i r o n s t o r e s i n normal s u b j e c t s . J_j_ C l i n .  Path. 26:770-772, 1973. Wheby, M. E f f e c t of i r o n therapy on serum f e r r i t i n l e v e l s i n i r o n - d e f i c i e n c y anemia. Blood 56(1):138-140, 1980. Wintrobe, W. C l i n i c a l Hematology. 8th Ed • P h i l a d e l p h i a , Lea and F e b i g e r , 1981, p. 609. Wirth, J.C., T.G. Lohman, J.P. A v a l l o n e , T. Sh r i n e , and R.A. B o i l e a u . The e f f e c t of p h y s i c a l t r a i n i n g on the serum i r o n l e v e l s of c o l l e g e - a g e women. Med. S c i . Sports 10(3):223-226, 1978. W i s h n i t z e r , R.f E. V o r s t , and A. B e r r e b i . Bone marrow i r o n d e p r e s s i o n i n c o m p e t i t i v e d i s t a n c e runners. I n t . J . Sports  Med. 4(l):27-30, 1983. Yoshimura, H. Anemia during p h y s i c a l t r a i n i n g ( s p o r t s anemia). Nutr. Rev. 28:251-253, 1970. Yoshimura, H., T. Inoue, T. Yamada, and K. S h i r a k i . Anemia du r i n g hard p h y s i c a l t r a i n i n g ( s p o r t s anemia) and i t s c a u s a l mechanism with s p e c i a l r e f e r e n c e to p r o t e i n n u t r i t i o n . World Rev. Nutr. D i e t . 35:1-86, 1980. 76 

Cite

Citation Scheme:

        

Citations by CSL (citeproc-js)

Usage Statistics

Share

Embed

Customize your widget with the following options, then copy and paste the code below into the HTML of your page to embed this item in your website.
                        
                            <div id="ubcOpenCollectionsWidgetDisplay">
                            <script id="ubcOpenCollectionsWidget"
                            src="{[{embed.src}]}"
                            data-item="{[{embed.item}]}"
                            data-collection="{[{embed.collection}]}"
                            data-metadata="{[{embed.showMetadata}]}"
                            data-width="{[{embed.width}]}"
                            async >
                            </script>
                            </div>
                        
                    
IIIF logo Our image viewer uses the IIIF 2.0 standard. To load this item in other compatible viewers, use this url:
https://iiif.library.ubc.ca/presentation/dsp.831.1-0077283/manifest

Comment

Related Items