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The effect of continuous and interval warm-up on post-exercise bronchoconstriction McLuckie, Sandra Lynn 1986

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THE EFFECT OF CONTINUOUS AND INTERVAL WARM-UP ON POST-EXERCISE BRONCHOCONSTRICTION by SANDRA LYNN MCLUCKIE B . P . E . Univers i ty of B r i t i s h Columbia, 1983. A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER IN PHYSICAL EDUCATION in THE FACULTY OF GRADUATE STUDIES Physical Education and Recreation We accept th i s thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA December 1986 © Sandra Lynn McLuckie, 1986. 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 /^/u^p&u.<^~^ /^c^cccx^^^ The University of British Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 Date /%u_<~J a ? / ^ ?  ABSTRACT S e v e r a l 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 e x p e r i e n c e an i n c r e a s e i n a i r w a y r e s i s t a n c 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 . Warm-up p r i o r t o e x e r c i s e has been s u g g e s t e d as a n o n - i n v a s i v e means of r e d u c i n g or e l i m i n a t i n g t h i s c o n d i t i o n . To d e t e r m i n e t h e e f f e c t of warm-up on p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n , t w e l v e m o d e r a t e l y t r a i n e d e x e r c i s e - i n d u c e d a s t h m a t i c s (age = 26.5 y r s ; -1 -1 h t . = 169.2 cm; wt. = 64.3 kg; VO max = 52.5ml.kg .min ; PC20 = -1 2 1.00 mg.ml ) were t e s t e d under t h r e e e x p e r i m e n t a l c o n d i t i o n s . C o n t i n u o u s warm-up (CW) c o n s i s t e d of 15 m i n u t e s o f t r e a d m i l l r u n n i n g a t a v e l o c i t y c o r r e s p o n d i n g t o 60% VO max f o l l o w e d by an 2 e x e r c i s e - c h a l l e n g e t e s t (ET= 6 m i n u t e s a t 90% VO max). The 2 i n t e r v a l warm-up (IW) i n v o l v e d 8 x 30 s e c o n d s p r i n t s a t an i n t e n s i t y e q u i v a l e n t t o 100% V0 max (1.5 m i n u t e s r e s t between 2 s p r i n t s ) , f o l l o w e d by an ET. The no warm-up (NW) i n v o l v e d o n l y t h e ET, and a c t e d as t h e c o n t r o l . FEV , FVC, and MMEFR were 1.0 measured v i a t h e Br e o n s p i r o m e t e r p r i o r t o warm-up (CW and IW), ET, and e v e r y 2 m i n u t e s d u r i n g a 25 minute p a s s i v e r e c o v e r y p e r i o d . P o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n was t a k e n as t h e l a r g e s t d e c r e a s e i n %FEV , %FVC, and %MMEFR d u r i n g t h e r e c o v e r y 1.0 p e r i o d . S i g n i f i c a n t d i f f e r e n c e s were d e t e c t e d i n %FEV (34.6, 1.0 50.0, 30.0: p = 0.009); %FVC (16. 7 , 30.2, 10.7: p = 0.05); and %MMEFR ( ( 2 9 . 7 , 43.4, 21.0: p = 0.03), i n c o m p a r i n g NW, CW, and IW, r e s p e c t i v e l y . A S c h e f f e ' s t e s t d e t e c t e d s i g n i f i c a n c e (p<0.05) between NW and CW f o r a l l 3 dependent v a r i a b l e s . No s i g n i f i c a n c e between NW and IW or IW and CW o c c u r r e d . T h i s d a t a i n d i c a t e s t h a t a c o n t i n u o u s warm-up of 15 m i n u t e s a t 60% V0 max can 2 s i g n i f i c a n t l y d e c r e a s e p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i n m o d e r a t e l y t r a i n e d a t h l e t e s . i i i TABLE OF CONTENTS ABSTRACT i i L I S T OF TABLES v i i L I S T OF FIGURES • v i i i ACKNOWLEDGEMENTS i x INTRODUCTION 1 METHODS 6 S u b j e c t s 6 F i t n e s s A s s e s s m e n t 6 Pulmonary F u n c t i o n A s s e s s m e n t 7 B r o n c h i a l R e a c t i v i t y 7 E x e r c i s e - C h a l l e n g e T e s t 8 Study D e s i g n " 8 S t a t i s t i c a l A n a l y s i s 10 RESULTS 12 S u b j e c t s 12 Pulmonary F u n c t i o n M e asures 12 Pulmonary F u n c t i o n M e asures ( R e l a t i v e t o Base) 13 E n v i r o m e n t a l C o n d i t i o n s 14 DISCUSSION 21 CONCLUSIONS 27 REFERENCES 28 i v APPENDICES 34 A. REVIEW OF LITERATURE 35 I n t r o d u c t i o n 35 H i s t o r i c a l Review 36 C l i n i c a l P r e s e n t a t i o n 38 Methods of T e s t i n g . . . 38 Lung M e c h a n i c s and B l o o d Gas Changes 39 P a t h o p h y s i o l o g y ^2 R e f r a c t o r y P e r i o d 46 F a c t o r s A f f e c t i n g t h e M a g n i t u d e of Response 47 -Type of E x e r c i s e 47 - I n t e r m i t t e n t E x e r c i s e 48 - I n t e n s i t y and D u r a t i o n 49 - A e r o b i c F i t n e s s 49 - E n v i r o m e n t a l C o n d i t i o n s 50 - P r e - e x e r c i s e M e d i c a t i o n 51 -Warm-up 51 P r e v i o u s S t u d i e s 52 B. INDIVIDUAL PHYSIOLOGICAL DATA 54 C. INDIVIDUAL PULMONARY FUNCTION DATA 55 D. INDIVIDUAL PULMONARY FUNCTION DATA: %CHANGE 56 E. INDIVIDUAL FEV1.0 DATA 57 F. INDIVIDUAL MMEFR DATA 58 G. INDIVIDUAL FVC DATA 59 H. RESPIRATORY HEAT LOSS 60 I . RESPIRATORY HEAT LOSS DATA 61 v J . EXERCISE-CHALLENGE PROTOCOL (BASELINE) 63 K. EXERCISE-CHALLENGE PROTOCOL (CONTINUOUS WARM-UP) 64 L. EXERCISE-CHALLENGE PROTOCOL (INTERVAL WARM-UP) 65 vi L I S T OF TABLES TABLE I : PHYSIOLOGICAL CHARACTERISTICS 15 TABLE I I : BASELINE FEV 16 1.0 TABLE I I I : MEAN PULMONARY FUNCTION CHANGES 17 TABLE IV: ENVIROMENTAL CONDITIONS 18 TABLE V: RESPIRATORY HEAT LOSS 19 L I S T OF FIGURES FIGURE I : STUDY DESIGN 9 FIGURE I I : COMPARISON OF PULMONARY FUNCTION MEANS 2 0 vi i i ACKNOWLEDGEMENTS I would l i k e to take t h i s o p p o r t u n i t y to thank the s u b j e c t s whom devoted t h e i r time and energy to make t h i s study p o s s i b l e . I would l i k e to thank Dr. Jack Taunton and Dr. Dave S t i r l i n g f o r t h e i r guidance and a s s i s t a n c e i n t h i s study. A s p e c i a l thanks to my a d v i s o r and t h e s i s chairman Dr. Don McKenzie f o r h i s support and v a l u a b l e a d v i c e throughout the study. F i n a l l y , I am very g r a t e f u l to my f a m i l y and f r i e n d s f o r t h e i r p a t i e n c e , understanding and i n c e n t i v e to complete t h i s p r o j e c t . IX INTRODUCTION B r o n c h i a l asthma i s t h e most common r e s p i r a t o r y d i s o r d e r i n N o r t h A m e r i c a and i s p r e s e n t i n o v e r 8 m i l l i o n i n d i v i d u a l s ( M a r l e y , 1 9 7 7 ) . D u r i n g c h i l d h o o d , b r o n c h i a l a s t h m a i s t w o f o l d i n m a l e s compared w i t h f e m a l e s , h o w e v e r , i n a d u l t s i t i s se e n e q u a l l y i n b o t h s e x e s . Over 9 5% o f t h e s e a t o p i c , and a s m a l l p e r c e n t a g e o f n o n - a t o p i c ( G o d f r e y , 1 9 7 5 ) , i n d i v i d u a l s e x p e r i e n c e an i n c r e a s e i n a i r w a y r e s i s t a n c 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 ( M o n k s , 1980; F i t c h , 1 9 7 5 ) . T h i s c o n d i t i o n i s r e f e r r e d t o as e x e r c i s e - i n d u c e d b r o n c h o s p a s m ( E I B ) o r e x e r c i s e - i n d u c e d asthma ( E I A ) . Many i n d i v i d u a l s w i t h t h i s d i s o r d e r a v o i d s p o r t s p a r t i c i p a t i o n , h o w e v e r , o t h e r s have engaged i n a v a r i e t y o f a t h l e t i c s and many have a c h i e v e d e l i t e p e r f o r m a n c e s . The s e v e r i t y o f b r o n c h o c o n s t r i c t i o n b r o u g h t a b o u t by e x e r c i s e c a n be r e d u c e d o r e l i m i n a t e d by s e v e r a l f a c t o r s : d e c r e a s e d i n t e n s i t y and d u r a t i o n of e x e r c i s e , i n t e r m i t t e n t e x e r c i s e , warm-humid e n v i r o n m e n t , p r e - e x e r c i s e m e d i c a t i o n , i m p r o v e d a e r o b i c f i t n e s s , and warm-up ( M o r t o n e t a l , 1981; F i t c h , 1976; M a r l e y , 1 9 7 7 ) . A i r w a y r e s i s t a n c e i s most f r e q u e n t l y m e asured by f o r c e d e x p i r a t o r y volume i n one s e c o n d (FEV 1 . 0 ) , m a x i m a l m i d - e x p i r a t o r y f l o w r a t e (MMEFR), and peak e x p i r a t o r y f l o w r a t e ( P E F R ) , w i t h t h e use o f a p u l m o n a r y f u n c t i o n s p i r o m e t e r ( A n d e r s o n e t a l , 1 9 7 5 ) . An i n c r e a s e i n a i r w a y r e s i s t a n c e o f 15-20% i s s i g n i f i c a n t o f m i l d b r o n c h o s p a s m , 20-30% f o r m i l d - m o d e r a t e b r o n c h o s p a s m , and g r e a t e r t h a n 30% i s i n d i c a t i v e o f s e v e r e b r o n c h o s p a s m ( A n d e r s o n 1 e t a l , 1975; K a t z , 19 8 3 ) 4. T h i s i n c r e a s e d r e s i s t a n c e i s b r o u g h t a b o u t by b r o n c h i a l w a l l edema, mucus g l a n d h y p e r s e c r e t i o n and b r o n c h o c o n s t r i c t i o n o f smooth m u s c l e c a u s i n g an i n d i v i d u a l t o be p r e s e n t w i t h s i g n s of w h e e z i n g , d y s p n e a , c o u g h i n g , c h e s t t i g h t n e s s , i n c r e a s e d n a s a l s e c r e t i o n and sputum p r o d u c t i o n ( G u y t o n , 1 9 8 2 ) . I n a d d i t i o n , an i n c r e a s e i n a l v e o l a r t o a r t e r i a l o x y g e n t e n s i o n o c c u r s , c a u s i n g an i n e q u a l i t y of t h e v e n t i l a t i o n / p e r f u s i o n r a t i o ( K a t z , 1 9 8 3 ) . As a r e s u l t , i n i n d i v i d u a l s w i t h c h r o n i c a s t h m a , b l o o d gas c h a n g e s ( i n c r e a s e i n a r t e r i a l pC02 and d e c r e a s e i n a r t e r i a l p02) a s s o c i a t e d w i t h E I A , may d e c r e a s e an a t h l e t e s p e r f o r m a n c e ( K a t z , 1983; A s t r a n d and R o d a h l , 1977; Fox and Mathews, 1 9 8 1 ) . An a p p r o p r i a t e e x e r c i s e s t i m u l u s w i l l p r o v o k e a c h a r a c t e r i s t i c p h y s i o l o g i c a l r e s p o n s e i n an e x e r c i s e - i n d u c e d a s t h m a t i c , a l t h o u g h t h e m a g n i t u d e o f t h e r e s p o n s e may v a r y v / i t h t h e c l i n i c a l s t a t e ( G o d f r e y , 1975; K a t z , 1 9 8 3 ) . D u r i n g t h e i n i t i a l 4 m i n u t e s of a s i x - m i n u t e p e r i o d o f v i g o r o u s e x e r c i s e (>80% maximum p r e d i c t e d h e a r t r a t e ) many i n v e s t i g a t o r s r e p o r t a b r o n c h o d i l a t i o n of t h e a i r w a y , r e f l e c t i n g an i n c r e a s e i n p u l m o n a r y f u n c t i o n ( G o d f r e y , 1975; I n b a r e t a l , 1 9 8 1 ) . S t i r l i n g and c o l l e a g u e s ( 1 9 8 3 ) r e p o r t a s i g n i f i c a n t d e c r e a s e i n p u l m o n a r y r e s i s t a n c e ( R l _ ) d u r i n g e x e r c i s e i n a s t h m a t i c i n d i v i d u a l s . H e a l t h y i n d i v i d u a l s e x e r c i s i n g a t 75% of t h e i r maximum p r e d i c t e d h e a r t r a t e , h o w e v e r , show no s i g n i f i c a n t d i f f e r e n c e i n ( S t i r l i n g e t a l , 1 9 8 3 ) . P u l m o n a r y r e s i s t a n c e i s an i n v a s i v e m easure w h i c h has a g r e a t e r a c c u r a c y and r e l i a b i l i t y i n 2 d e t e r m i n i n g l u n g f u n c t i o n . T h i s b r o n c h o d i l a t i o n i s b e l i e v e d t o be c a u s e d by an i n c r e a s e i n s y m p a t h e t i c d r i v e d u r i n g e x e r c i s e ( G o d f r e y , 1 9 7 5 ) . F o l l o w i n g e x e r c i s e , c o n s t r i c t i o n o f t h e a i r w a y s o c c u r s and r e s u l t i n g i n a d e c r e a s e i n l u n g f u n c t i o n . At t h e c o m p l e t i o n of t h e 6 m i n u t e e x e r c i s e c h a l l e n g e t e s t , b r o n c h o c o n s t r i c t i o n c o n t i n u e s , r e a c h i n g a peak a t 3-4 m i n u t e s p o s t e x e r c i s e i n c h i l d r e n and 4-6 m i n u t e s i n a d u l t s ( G o d f r e y , 1 9 7 5 ) . The a i r w a y s b e g i n t o r e t u r n t o n o r m a l between 20-60 m i n u t e s . A s t h m a t i c i n d i v i d u a l s p r e s e n t a g r e a t e r t h a n 15% d e c r e a s e i n FEV1.0 f r o m b a s e l i n e v a l u e s w i t h i n 10 m i n u t e s of c o m p l e t e d e x e r c i s e ( K a t t a n e t a l , 1 9 3 3 ) ; 98% o f a h e a l t h y p o p u l a t i o n have a f a l l o f l e s s t h a n 15% f o l l o w i n g e x e r c i s e ( B u r r e t a l , 1 9 7 4 ) . The p a t h o g e n e s i s o f EIA i s n o t f u l l y u n d e r s t o o d d e s p i t e t h e numerous s t u d i e s . However, t h e most w i d e l y a c c e p t e d h y p o t h e s i s i s a c o o l i n g and d e h y d r a t i o n of t h e mast c e l l s r e s u l t i n g i n b r o n c h o c o n s t r i c t o r m e d i a t o r r e l e a s e ( E i s e n s t a d t e t a1 , 1984; K a t z , 1983; D e a l e t a l , 1979a; G o d f r e y , 1 9 7 5 ) . M e d i a t o r s s u c h as h i s t a m i n e , SRS-A ( s l o w r e a c t i n g s u b s t a n c e s of a n a p h y l a x i s ) and ECF-A ( e o s i n o p h i l c h e m o t a c t i c f a c t o r ) a c t d i r e c t l y on b r o n c h i a l smooth m u s c l e c e l l s . D r u g s s u c h as DSCG ( c r o m o l y n ) , 2 a d r e n e r g i c a g o n i s t s , c a l c i u m a n t a g o n i s t s and d i e t h y l c a r b a m a z i n e , i n h i b i t mast c e l l d e g r a n u l a t i o n by i n h i b i t i n g SRS-A p r o d u c t i o n and t h e r e f o r e p r e v e n t i n g EIA ( L e e e t a l , 1 9 8 4 ) . The d e v e l o p m e n t of a r e f r a c t o r y p e r i o d i n many e x e r c i s e -i n d u c e d a s t h m a t i c s , a f t e r r e p e a t e d e x e r c i s e , has l e d t o t h e 3 t h e o r y o f m e d i a t o r s t o r e d e p l e t i o n and a t i m e p e r i o d r e q u i r e d f o r r e p l e n i s h m e n t o f s t o r e s ( G o d f r e y e t a l , 1 9 7 3 ) . S e v e r a l i n v e s t i g a t o r s have d e m o n s t r a t e d t h a t two c o n s e c u t i v e e x e r c i s e c h a l l e n g e s , p e r f o r m e d w i t h i n two h o u r s o f e a c h o t h e r , r e s u l t s i n t h e s e c o n d c h a l l e n g e b e i n g a t t e n u a t e d by t h e f i r s t ( B a r - Y i s h a y e t a l , 1984; Edmunds e t a l , 1978; S t r a u s s e t a l , 1978; G o d f r e y , 1 9 7 7 ) . I n a d d i t i o n , i t i s t h e o r i z e d t h a t warm-up, i n t h e e x e r c i s e - i n d u c e d a s t h m a t i c , p r i o r t o e x e r c i s e may g r a d u a l l y d i s c h a r g e t h e b r o n c h i a l c o n s t r i c t i n g m e d i a t o r s f r o m t h e mast c e l l s , l e a d i n g t o a d e p l e t i o n i n m e d i a t o r s t o r e s w h i c h may r e q u i r e a p e r i o d o f t i m e f o r r e s y n t h e s i s ( G o d f r e y , 1 9 7 7 ) . T h i s has l e d t o t h e b e l i e f t h a t warm-up may a l t e r t h e i n c i d e n c e and s e v e r i t y o f b r o n c h o c o n s t r i c t i o n i n s u b j e c t s w i t h EIA ( M o r t o n e t a l , 1 9 8 1 ) . S e v e r a l a n e c d o t a l r e p o r t s s u g g e s t l e s s b r o n c h o c o n s t r i c t i o n f o l l o w i n g a warm-up of s t r e t c h i n g , j u m p i n g , s h o r t s p r i n t s , and g y m n a s t i c a c t i v i t i e s f o r 20 m i n u t e s p r i o r t o e x e r c i s e ( M o r t o n e t a l , 1981; E i s e n s t a d t e t a l , 1984; G o d f r e y , 1977; F i t c h , 1 9 7 5 ) . However, o n l y two s t u d i e s have been u n d e r t a k e n t o e x a m i n e t h e e f f e c t o f warm-up on p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i n e x e r c i s e - i n d u c e d a s t h m a t i c s . M o r t o n and c o l l e a g u e s ( 1 9 7 9 ) , t e s t e d 10 male and 8 f e m a l e a t o p i c i n d i v i d u a l s ( a g e s 11-33 y e a r s ) t o d e t e r m i n e t h e e f f e c t o f 'warm-up' on e x e r c i s e - i n d u c e d a s t h m a . E a c h s u b j e c t p e r f o r m e d 5 m i n u t e s o f s u b m a x i m a l t r e a d m i l l r u n n i n g t o a c h i e v e a h e a r t r a t e o f 8 5 % o f p r e d i c t e d maximum f o r a g e . One o f t h e two t e s t s , was k p r e c e e d e d by a warm-up e x e r c i s e of 3 m i n u t e s o f w a l k i n g a t 60% of p r e d i c t e d m a x i m a l h e a r t r a t e . A l t h o u g h M o r t o n f a i l e d t o show s i g n i f i c a n c e i n p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n b e t ween t h e two t e s t s , he recommended t h a t a l o n g e r , more i n t e n s e 'warm-up' i n v o l v i n g i n t e r v a l e x e r c i s e needs t o be e v a l u a t e d . S c h n a l l and Landau ( 1 9 8 0 ) i n v e s t i g a t e d f o u r m a l e s and two f e m a l e s ( a g e s 12 t o 31 y e a r s ) u n d e r t h r e e e x p e r i m e n t a l , ' c o n d i t i o n s : A; 2 x 6 m i n u t e r u n s w i t h a 4 9 m i n u t e r e s t b e t ween r u n s : B; 6 m i n u t e r u n , f o l l o w e d by 10 m i n u t e s o f r e s t and 7 x 30 s e c o n d s p r i n t s ( 2 . 5 m i n u t e s r e s t between s p r i n t s ) : and C; 7 x 30 s e c o n d s p r i n t s ( 2 . 5 m i n u t e s r e s t b e t ween s p r i n t s ) f o l l o w e d by 20 m i n u t e s o f r e s t and a 6 m i n u t e r u n . I t was f o u n d t h a t t h e s h o r t s p r i n t s d i d n o t i n d u c e b r o n c h o c o n s t r i c t i o n and r e s u l t e d i n l e s s b r o n c h o c o n s t r i c t i o n a f t e r a 6 m i n u t e r u n . T hese c o n c l u s i o n s were d e s c r i p t i v e , and i t i s recommended t h a t a more homogeneous g r o u p u n d e r g o e x a m i n a t i o n , w i t h s t a t i s t i c a l a n a l y s i s . I t was, t h e r e f o r e , t h e p u r p o s e o f t h i s s t u d y t o compare t h e s e v e r i t y of b r o n c h o c o n s t r i c t i o n f o l l o w i n g a 6 m i n u t e e x e r c i s e c h a l l e n g e t e s t i n e x e r c i s e - i n d u c e d a s t h m a t i c s w i t h a c o n t i n u o u s warm-up v e r s u s no warm-up and w i t h an i n t e r v a l warm-up v e r s u s no warm-up. I n a d d i t i o n , t h i s s t u d y i n v e s t i g a t e d i f t h e i n t e r v a l and c o n t i n u o u s 'warm-ups' d i f f e r e d i n t h e d e g r e e of p o s t -e x e r c i s e b r o n c h o c o n s t r i c t i o n . 5 METHODS SUBJECTS : Twenty m o d e r a t e l y t r a i n e d a t h l e t e s ( a g e s 17 t o 42 y e a r s ) w i t h e x e r c i s e - i n d u c e d asthma a c t e d as v o l u n t e e r s f o r t h e s t u d y . They were r e c r u i t e d t h r o u g h a d v e r t i s e m e n t i n r e c r e a t i o n a l f a c i l i t i e s and l o c a l gyms, p e r s o n a l c o n t a c t , and h o s p i t a l r e c o r d s . A l l s u b j e c t s were r e c e i v i n g - a g o n i s t s i n a e r o s o l form ( s a l b u t a m o l , f e n e t e r o l ) a n d/or i n t a l ( s o d i u m c h r o m o g l y c a t e ) t o c o n t r o l t h e i r E.I.A. S i x t e e n i n d i v i d u a l s c o m p l e t e d t h e b a s e l i n e c r i t e r i a r e q u i r e d f o r i n c l u s i o n i n t h e s t u d y . They a c h i e v e d a -1 -1 VO max o f g r e a t e r or e q u a l t o 45 ml.kg .min , a p o s i t i v e 2 h i s t a m i n e c h a l l e n g e t e s t , and a g r e a t e r t h a n 15% f a l l i n FEV 1.0 f o l l o w i n g an e x e r c i s e - c h a l l e n g e t e s t . T h e s e i n d i v i d u a l s were non-smokers and d i d not p r e s e n t any a d d i t i o n a l pulmonary f u n c t i o n p r o b l e m s . The s u b j e c t s were i n a p e r i o d o f r e m i s s i o n a t t h e t i m e o f t e s t i n g and d i d not r e c e i v e m e d i c a t i o n 12 h o u r s p r i o r to t r e a d m i l l t e s t i n g . In a d d i t i o n , t h e y d i d not p a r t i c i p a t e i n any form o f p h y s i c a l a c t i v i t y or i n g e s t c a f f e i n e f o u r h o u r s p r i o r t o th e t e s t i n g s e s s i o n s . FITNESS ASSESSMENT: Maximal oxygen u p t a k e (VO max) and maximal h e a r t r a t e were 2 o b t a i n e d by a t r e a d m i l l r u n a t t h e Buchanan F i t n e s s L a b o r a t o r y . -1 F o l l o w i n g a 5-minute warm-up a t 2.22 m.sec. , 2 p u f f s of the i n d i v i d u a l s p r e s c r i b e d b r o n c h o d i l a t o r were t a k e n . F i v e m i n u t e s l a t e r , e ach i n d i v i d u a l began a t r e a d m i l l run w i t h an i n i t i a l 6 -1 v e l o c i t y o f 2.22 m.sec ., which a u t o m a t i c a l l y i n c r e a s e d 0.22 -1 m.sec e v e r y m i n u t e u n t i l v o l u n t a r y e x h a u s t i o n . H e a r t r a t e was m o n i t o r e d by d i r e c t e l e c t r o c a r d i o g r a p h y ( A v i o n i c s 4000 E l e c t r o c a r d i o g r a p h ) . E x p i r e d a i r was c o n t i n u o u s l y sampled and p r o c e s s e d a t 15 second i n t e r v a l s f o r t h e d e t e r m i n a t i o n of r e s p i r a t o r y gas exchange v a r i a b l e s (VE, VCO . R, e x c e s s CO , and 2 2 t e m p e r a t u r e ) . The Beckman M e t a b o l i c Measurement C a r t i n t e r f a c e d t o a H e w l e t t - P a c k a r d 3052-A Data A q u i s i t i o n System was used f o r d a t a c o l l e c t i o n and a n a l y s i s . The mean f o r t h e f o u r h i g h e s t c o n s e c u t i v e v a l u e s f o r oxygen c o n s u m p t i o n and h e a r t r a t e were t a k e n as t h e VO max and maximal h e a r t r a t e , r e s p e c t i v e l y (Rhodes 2 e t a l , 1983). PULMONARY FUNCTION ASSESSMENT: Lung volumes were t a k e n p r i o r t o t h e s t u d y t o d e t e r m i n e t h e p r e s e n c e of any a d d i t i o n a l pulmonary d i s e a s e . I n s p i r a t o r y r e s e r v e volume, t i d a l volume, f u n c t i o n a l r e s i d u a l c a p a c i t y , e x p i r a t o r y r e s e r v e volume, v i t a l c a p a c i t y , r e s i d u a l volume, and t o t a l l u n g c a p a c i t y were measured on a C o l l i n s S p i r o m e t e r a t t h e R e s p i r a t o r y L a b o r a t o r y , H e a l t h S c i e n c e C e n t e r . Dynamic f l o w r a t e s were o b t a i n e d by t h e C o l l i n s S p i r o m e t e r , a t t h e H e a l t h S c i e n c e C e n t e r H o s p i t a l , under th e f o l l o w i n g c o n d i t i o n s ; no h i s t a m i n e , h i s t a m i n e i n h a l a t i o n , s a l i n e i n h a l a t i o n , and v e n t o l i n i n h a l a t i o n . Flow r a t e s o b t a i n e d i n c l u d e d FEV , MMEFR, and FVC. 1.0 7 BRONCHIAL REACTIVITY: I n d i v i d u a l s completed a histamine c h a l l e n g e t e s t , administered by a R e s p i r a t o r y T e c h n i c i a n at the Health Sciences Center H o s p i t a l . A continuous breathing method was used, which i n v o l v e d i n h a l a t i o n of i n c r e a s i n g c o n c e n t r a t i o n s of histamine by t i d a l volume breathing f o r two minute i n t e r v a l s . Pulmonary f u n c t i o n was assessed a f t e r each c o n c e n t r a t i o n was i n h a l e d u n t i l a f a l l i n FEV of 20% or more o c c u r r e d . A 20% or g r e a t e r f a l l 1.0 i n FEV with a histamine c o n c e n t r a t i o n (PC20) l e s s than 8.0 - 1 1.0 mg.ml was considered to be a p o s i t i v e t e s t ( i n d i c a t i v e of b r o n c h i a l h y p e r - r e a c t i v i t y - - d i a g n o s t i c of asthma). EXERCISE-CHALLENGE TEST: The s u b j e c t s underwent an e x e r c i s e - c h a l l e n g e t e s t i n v o l v i n g a s i x minute t r e a d m i l l run at 90% V0 max, f o r c o n f i r m a t i o n of 2 d i a g n o s i s and to act as a c o n t r o l f o r the study, at the E x e r c i s e Physiology Laboratory, War Memorial Gymnasium, U.B.C. T r e a d m i l l speed was determined by previous values achieved during the f i t n e s s assessment. Pulmonary f u n c t i o n measures were c o l l e c t e d , v i a a Breon spirometer (Model 2A00: Breon L a b o r a t o r i e s I n c . ) , p r i o r to the t e s t and every two minutes during a 25 minute passive recovery f o l l o w i n g the t e s t . P o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n was taken as the l a r g e s t decrease i n % FEV , %FVC and %MMEFR during recovery. T h i s e x e r c i s e 1.0 c h a l l e n g e t e s t was used to confirm a b r o n c h o c o n s t r i c t i v e response to an e x e r c i s e c h a l l e n g e t e s t , i n a d d i t i o n to serve as a c o n t r o l 8 f o r the s t u d y . STUDY DESIGN: H a v i n g c o m p l e t e d b a s e l i n e c r i t e r i a , each s u b j e c t t h e n p a r t i c i p a t e d i n two t e s t i n g s e s s i o n s , on c o n s e c u t i v e d a y s . S u b j e c t s were randomly l a b e l l e d and a c o u n t e r b a l a n c i n g o f c o n d i t i o n s and s u b j e c t s o c c u r r e d . E ach s e s s i o n i n c l u d e d a T r e a t m e n t I n t e r v e n t i o n , a 2-minute R e s t P e r i o d , an E x e r c i s e -c h a l l e n g e T e s t and a P a s s i v e R e c o v e r y ( F i g u r e 1.) TREATMENT REST EX CHAL RECOVERY C o n t r o l A: Con W-up B: I n t W-up 1 T — 1 1 1 1 1 1 1 1 I r — — t -0 .5 2 4 6 8 10 12 14 16 20 25 Base P o s t Rx P o s t Ex (15 min) (2 min) (6 min) (25 min) FIGURE 1: STUDY DESIGN ( w i t h Time of Pulmonary F u n c t i o n M e a s u r e s ) T r e a t m e n t A, C o n t i n u o u s Warm-up, c o n s i s t e d o f a 15-minute c o n t i n u o u s t r e a d m i l l r u n a t an i n t e n s i t y e q u i v a l e n t t o 60% VO 2 max. T r e a t m e n t B, I n t e r v a l Warm-up, c o n s i s t e d of 8 x 30 se c o n d s p r i n t s on t h e t r e a d m i l l w i t h 1.5 m i n u t e s r e s t between s p r i n t s . The i n t e n s i t y of t h e s p r i n t s was a t a t r e a d m i l l v e l o c i t y c o r r e s p o n d i n g t o 100% V0 max c a l c u l a t e d from t h e i n i t i a l f i t n e s s 2 a s s e s s m e n t . F o l l o w i n g t h e t r e a t m e n t i n t e r v e n t i o n , and a 2 minute r e s t 9 p e r i o d f o r pulmonary f u n c t i o n measurements and t r e a d m i l l speed change, an e x e r c i s e - c h a l l e n g e t e s t , was u n d e r t a k e n . The t i m e of th e pulmonary f u n c t i o n measures a r e n o t e d i n F i g u r e 1. A b a s e l i n e measure was t a k e n p r i o r t o t r e a t m e n t i n t e r v e n t i o n ( t h e h i g h e s t o f t h r e e v a l u e s was r e c o r d e d ) . A p r e - e x e r c i s e c h a l l e n g e v a l u e was t a k e n 1 minute p r i o r t o t h e e x e r c i s e - c h a l l e n g e t e s t . E l e v e n p o s t - e x e r c i s e c h a l l e n g e measures were r e c o r d e d d u r i n g t h e r e c o v e r y phase a t t h e f o l l o w i n g t i m e s : .5, 2, 4, 6, 8, 10, 12, 14, 16. 20, and 25 m i n u t e s . P e r c e n t f a l l i n FEV , MMEFR, and 1.0 FVC were c a l c u l a t e d by u s i n g t h e l o w e s t v a l u e o b t a i n e d d u r i n g t h e r e c o v e r y and e n t e r e d i n t o t h e f o l l o w i n g e q u a t i o n : P r e - i n t e r v e n t i o n - Lowest V a l u e % F a l l = x 100 P r e - i n t e r v e n t i o n A d d i t i o n a l measurements t a k e n t h r o u g h o u t t e s t i n g s e s s i o n s i n c l u d e d ambient t e m p e r a t u r e and p r e s s u r e , r e l a t i v e h u m i d i t y . E x p i r e d gas volume was m o n i t o r e d by a P a r k i n s o n - C o w a n Gas Meter ( w i t h a p o t e n t i o m e t e r ) and r e c o r d e d on a Beckman R611 C h a r t R e c o r d e r . E x p i r e d gas t e m p e r a t u r e was measured by a YSI T e l e -t h e r m i s t e r , by means o f a 409 S w i t o g r a f t l e a d p o s i t i o n e d i n the e x p i r a t o r y p o r t i o n o f the m o u t h p i e c e . The d a t a c o l l e c t e d was used t o c a l c u l a t e t h e water c o n t e n t o f t h e e x p i r e d a i r , and r e s p i r a t o r y h e a t l o s s ( R H L ) . CALIBRATION PROCEDURES: The B r e o n S p i r o m e t e r was c a l i b r a t e d a t t h e U.B.C. H e a l t h 10 S c i e n c e s H o s p i t a l p r i o r t o , and a t t h e c o m p l e t i o n , of t h e s t u d y . A 3 l i t e r c a l i b r a t i o n s y r i n g e (ATPS) was used t o d e t e c t a 1.6% e r r o r a t t h e s t a r t of t h e s t u d y and a 2.7% e r r o r a t t h e c o m p l e t i o n of t h e s t u d y . STATISTICAL ANALYSIS: The pulmonary f u n c t i o n d a t a was a n a l y s e d u s i n g 3 ' one-way ANOVAS. A S c h e f f e ' s t - t e s t was used t o d e t e r m i n e i n d i v i d u a l d i f f e r e n c e s between t r e a t m e n t s . E n v i r o m e n t a l d a t a was a n a l y z e d by an ANOVA f o r each dependent v a r i a b l e ( r e l a t i v e h u m i d i t y , ambient p r e s s u r e , ambient t e m p e r a t u r e and i n s p i r e d water c o n t e n t ) . B a s e l i n e FEV1.0 v a l u e s underwent a one-way ANOVA. Heat f l u x was c a l c u l a t e d u s i n g t h e RHL f o r m u l a p o s t u l a t e d by S t r a u s s (1978; see App e n d i x E ) . RHL was a n a l y z e d u s i n g a one-way ANOVA. S t a t i s t i c a l s i g n i f i c a n c e l e v e l f o r a l l a n a l y s i s was a t an a l p h a l e v e l of .05. 11 RESULTS S u b j e c t s : The p h y s i o l o g i c a l c h a r a c t e r i s t i c s of t h e t w e l v e s u b j e c t s who c o m p l e t e d th e s t u d y a r e l i s t e d i n T a b l e I . A l l were non-smokers, d i d not have any a d d i t i o n a l pulmonary f u n c t i o n a b n o r m a l i t i e s , and were i n a p e r i o d of r e m i s s i o n . They were a b l e t o w i t h h o l d m e d i c a t i o n a t l e a s t 8 h o u r s p r i o r t o t h e t e s t i n g s e s s i o n s and d i d not p a r t i c i p a t e i n any form of p h y s i c a l a c t i v i t y or i n g e s t c a f f e i n e f o r f o u r h o u r s p r i o r t o t e s t i n g . The d a t a on each i n d i v i d u a l was c o l l e c t e d w i t h i n a 2 week p e r i o d , between the months of March and September, w i t h t h e e x c e p t i o n of 2 i n d i v i d u a l s w hich r e q u i r e d 4 weeks t o c o m p l e t e the d a t a c o l l e c t i o n . S u b j e c t s were m o d e r a t e l y t r a i n e d , h a v i n g a VO max. range o f -1. -1 2 45.0 to 60.0 ml.kg min. . I n d i v i d u a l s were d i a g n o s e d as -1 h a v i n g e x e r c i s e - i n d u c e d asthma by a c h i e v i n g a PC < 4.0 mg.ml 20 on t h e h i s t a m i n e c h a l l e n g e t e s t , and e x p e r i e n c i n g a g r e a t e r t h a n 15% f a l l i n FEV upon c o m p l e t i o n o f an e x e r c i s e - c h a l l e n g e t e s t 1.0 (6 m i n u t e s t r e a d m i l l r u n n i n g a t a v e l o c i t y e q u i v a l e n t t o 90% V0 2 max . ) Pulmonary F u n c t i o n M e a s u r e s : B a s e l i n e FEV v a l u e s p r i o r t o e ach t e s t i n g s e s s i o n d i d not 1.0 s i g n i f i c a n t l y d i f f e r between c o n d i t i o n s ( T a b l e I I ) . Each s u b j e c t d e m o n s t r a t e d an FEV v a l u e w i t h i n 10% of b a s e l i n e v a l u e s 1.0 o b t a i n e d a t t h e h o s p i t a l d u r i n g t h e pulmonary f u n c t i o n t e s t i n g . 12 F o l l o w i n g t r e a t m e n t i n t e r v e n t i o n , e ach s u b j e c t s ' FEV was 1.0 w i t h i n a 12% d e c r e a s e of b a s e l i n e , e x c e p t f o r two s u b j e c t s who upon c o m p l e t i o n o f the i n t e r v a l s p r i n t s , had a g r e a t e r t h an 20% d e c r e a s e . These i n d i v i d u a l s d i d not p r o c e e d t o the e x e r c i s e c h a l l e n g e . They r e t u r n e d t h e f o l l o w i n g day t o r e p e a t t h e t e s t i n which b o t h were a b l e t o c o n t i n u e and c o m p l e t e t h e e x e r c i s e -c h a l l e n g e t e s t . F o l l o w i n g t h e c o n t i n u o u s warm-up, 5 i n d i v i d u a l s e x p e r i e n c e d b r o n c h o d i l a t i o n and one i n d i v i d u a l had no chan g e . In a d d i t i o n , 5 o t h e r i n d i v i d u a l s e x p e r i e n c e d b r o n c h o d i l a t i o n p o s t i n t e r v a l t r e a t m e n t . Pulmonary F u n c t i o n M e a s u r e s R e l a t i v e t o B a s e l i n e M e a s u r e s : The mean changes f o r FEV , MMEFR, and FVC f o r each 1.0 t r e a t m e n t a r e l i s t e d i n T a b l e I I I , and g r a p h i c a l l y p r e s e n t e d i n F i g u r e 2. T h e r e i s a s i g n i f i c a n t d i f f e r e n c e i n t h e p e r c e n t change of FEV between t h e 3 c o n d i t i o n s (p=.009). A S c h e f f e ' s 1.0 p o s t hoc c o m p a r i s o n r e v e a l e d a s i g n i f i c a n t d i f f e r e n c e (p<0.05) i n FEV between t h e c o n t r o l and t h e c o n t i n u o u s warm-up c o n d i t i o n s . 1.0 A mean d i f f e r e n c e between t h e s e t r e a t m e n t s was 17.3%. S i g n i f i c a n t d i f f e r e n c e s were shown f o r %MMEFR (p=.05) and %FVC (p=.03) o v e r t h e 3 c o n d i t i o n s . S c h e f f e ' s t e s t r e v e a l e d s i g n i f i c a n t c h a n g e s (p<0.05) i n %MMEFR and %FVC, between t h e c o n t r o l and c o n t i n u o u s warm-up c o n d i t i o n s . S c h e f f e ' s p o s t hoc c o m p a r i s o n s f a i l e d t o show s i g n i f i c a n t d i f f e r e n c e s between the c o n t r o l and i n t e r v a l warm-up c o n d i t i o n s , or between t h e c o n t i n u o u s warm-up and i n t e r v a l warm-up c o n d i t i o n , i n FEV , 1.0 13 MMEFR, and FVC. The c r i t e r i a f o r E I A was p r e s e n t i n 6 of the 12 s u b j e c t s f o l l o w i n g a c o n t i n u o u s warm-up and 11 o f t h e 12 s u b j e c t s f o l l o w i n g t h e i n t e r v a l warm-up. E n v i r o m e n t a l C o n d i t i o n s : Room t e m p e r a t u r e , r e l a t i v e h u m i d i t y and ambient p r e s s u r e showed no s i g n i f i c a n t d i f f e r e n c e s between c o n d i t i o n s ( T a b l e I V ) . Room t e m p e r a t u r e and r e l a t i v e h u m i d i t y r a n g e d from 18.5 t o 23.5 C and 50.0 t o 78.0%, r e s p e c t i v e l y . W i t h t h i s d a t a , t h e water c o n t e n t of i n s p i r e d a i r (WCi) was c a l c u l a t e d f o r each t e s t i n g s e s s i o n ( T a b l e I V ) . An a n a l y s i s o f v a r i a n c e r e v e a l e d no s i g n i f i c a n t d i f f e r e n c e i n WCi between t e s t i n g s e s s i o n s . T h r o u g h o u t t h e e x e r c i s e - c h a l l e n g e t e s t , e x p i r a t o r y gas volumes (Ve) and e x p i r a t o r y t e m p e r a t u r e ( T e ) were r e c o r d e d a t 1, 3, and 5 minute i n t e r v a l s d u r i n g t h e t e s t . The e x p i r a t o r y d a t a , c o m p l e t e d by 7 s u b j e c t s , was used t o c a l c u l a t e RHL ( S t r a u s s , e t a l , 1 9 7 8). The d a t a c o l l e c t e d a t t h e 5 minute p e r i o d was used as the s t e a d y s t a t e RHL. No s i g n i f i c a n t d i f f e r e n c e was f o u n d i n RHL between c o n d i t i o n s ( T a b l e V ) . TABLE I. PHYSIOLOGICAL CHARACTERISTICS (MEANS ± '1' SD) Age ( y e a r s ) 26.5 + 7.8 H e i g h t (cm) 169.2 + 9.5 Weight (kg) 64.3 + 10.3 -1 -1 VO max (ml.kg .min ) 52.5 +_ 4.7 2 -1 PC20 (mg.ml ) 1.00 + 1.4 15 TABLE I I . BASELINE VALUES OF FEV , MMEFR, F V C ( l i t e r s ; MEANS ± SD) ~~1 .0 FEV MMEFR FVC No Warm-up: C o n t . Warm-up: I n t . Warm-up: * p > .05 3.42 + 1.05 3.30 + .91 3.35 + .93 3.22 + 1.41 3.03 + 1.29 3.11 + 1.26 4.21 + 1 . 1 5 4.08 + 1.02 4.17 + 1.01 N o n - s i g n i f i c a n t 16 TABLE I I I . MEAN CHANGES IN PULMONARY FUNCTION MEASURES IN COMPARISON TO BASELINE MEASURES UNDER EACH CONDITION (MEANS ± SD) CONTROL CW IW %FEV1.0 34.6 + 16.3 16.7 + 11.2* 29.7 + 13.0 p=.009 %MMEFR 50.0 + 19.5 30.2 + 17.7* 43.4 + 20.3 p=.05 %FVC 30.0 + 12.3 10.7 + 7.7* 21.0 + 12.5 p=.03 * = p<0.05 C o n t r o l v s . C o n t i n u o u s Warm-up NW = C o n t r o l CW = C o n t i n u o u s Warm-up C o n d i t i o n IW = I n t e r v a l Warm-up C o n d i t i o n 17 TABLE IV. ENVIRONMENTAL CONDITIONS (n=12) CONTROL CW IW RT ( ° C ) : 20.9 + 2.1 21.3 + 2.1 21.5 + 1.6 RH ( % ) : 62.7 + 5.6 61.4 + 6.7 64.9 + 8.8 AP (ramHg): 757.2 + 5.3 756.3 + 5.4 758.1 + 5.4 WCi (mg.l ): 11.5 + 1.6 11.5 + 1.6 12.1 + 1.9 NW = No Warm-up C o n d i t i o n CW = C o n t i n u o u s Warm-up C o n d i t i o n IW = I n t e r v a l Warm-up C o n d i t i o n RT = Room t e m p e r a t u r e RH = R e l a t i v e H u m i d i t y AP = Ambient P r e s s u r e WCi = Water C o n t e n t o f I n s p i r e d a i r -1 18 TABLE V. RESPIRATORY HEAT LOSS DURING THE EXERCISE-CHALLENGE TEST AT 1, 3, AND 5 MINUTES ( k c a l / m i n ; MEANS ± SD) 1 MIN 3 MIN 5 MIN MEAN No Warm-up 1.04 + 0.47 1.25 + 0.42 1.32 + 0.41 1.20 + 0.42 C o n t . Warm-up 1.02 + 0.35 1.30 + 0.44 1.39 + 0.45 1.24 + 0.41 I n t . Warm-up 0.91 + 0.27 1.25 +.0.32 1.34 + 0.40 1.17 + 0.30 * N o n - s i g n i f i c a n t p=.94 (n=7) 19 FIGURE 2 . MEAN COMPARISON OF PULMONARY FUNCTION MEASURES RELEVANT TO BASELINE MEASURES 20 DISCUSSION I n d i v i d u a l s i n t h i s s t u d y were c o n f i r m e d as h a v i n g b r o n c h i a l -1 h y p e r - r e a c t i v i t y by a c h i e v i n g a PC <4.0 mg.ml d u r i n g a 20 h i s t a m i n e c h a l l e n g e t e s t and EIA was d e m o n s t r a t e d by a >15% f a l l i n FEV f o l l o w i n g an e x e r c i s e - c h a l l e n g e t e s t . Due t o t h e 1.0 l a r g e v a r i a b i l i t y i n the r e p r o d u c i b i l i t y o f EIA seen i n c h i l d r e n ( A n d e r s o n e t a l , 1975), a l l s u b j e c t s i n t h i s s t u d y were 18 y e a r s of age or o l d e r . V a r i a b l e pulmonary f u n c t i o n r e s p o n s e s a r e r e p o r t e d i n i n d i v i d u a l s w i t h v a r y i n g d e g r e e s of c a r d i o v a s c u l a r f i t n e s s ( A n d e r s o n e t a l , 1975; F i t c h and G o d f r e y , 1976), t h e r e f o r e , o n l y m o d e r a t e l y t r a i n e d a t h l e t e s (VO max = 45 t o 60 -1 -1 2 ml.kg. .min ) were u s e d . B a s e l i n e pulmonary f u n c t i o n measures were t a k e n p r i o r t o e a c h t e s t i n g s e s s i o n to e n s u r e an a b s e n c e o f b r o n c h o c o n s t r i c t i o n , and t o a c t as a b a s e l i n e v a l u e f o r t h e t e s t i n g s e s s i o n . A l l i n d i v i d u a l s were w i t h i n 10% of b a s e l i n e v a l u e s o b t a i n e d a t the H e a l t h S c i e n c e s C e n t e r H o s p i t a l d u r i n g t h e pulmonary f u n c t i o n t e s t i n g . F o l l o w i n g t r e a t m e n t i n t e r v e n t i o n , p r e - e x e r c i s e c h a l l e n g e m e a s u r e s , t a k e n 1 m i n u t e p r i o r t o t h e e x e r c i s e c h a l l e n g e , c o n f i r m e d t h a t b r o n c h o c o n s t r i c t i o n was not i n d u c e d by t h e t r e a t m e n t i n t e r v e n t i o n . These measures were w i t h i n a 15% d e c r e a s e o f b a s e l i n e v a l u e s , e x c e p t f o r 2 i n d i v i d u a l s ; t h e s e s u b j e c t s c o n s t r i c t e d g r e a t e r t h a n 20% of b a s e l i n e v a l u e s f o l l o w i n g t h e i n t e r v a l s p r i n t s . Upon r e t u r n i n g t h e n e x t day t o r e p e a t t h e t e s t , b o t h i n d i v i d u a l s c o n s t r i c t e d l e s s t h a n 15% o f 21 b a s e l i n e v a l u e s . The r e a s o n f o r c o n s t r i c t i o n on one day and not th e o t h e r i n d i c a t e s t h a t an u n c o n t r o l l e d s t i m u l u s ( s u c h a s : work or e m o t i o n a l s t r e s s ; e n v i r o m e n t a l or f o o d a l l e r g y , e t c . ) may have been p r e s e n t . At t h e c o m p l e t i o n o f t h e c o n t i n u o u s warm-up i n t e r v e n t i o n , p r e - e x e r c i s e c h a l l e n g e measures r e v e a l e d an i n c r e a s e i n %FEV and %MMEFR i n 5 i n d i v i d u a l s and no change i n 1.0 one. In a d d i t i o n , f o l l o w i n g t h e i n t e r v a l warm-up, 5 i n d i v i d u a l s d e m o n s t r a t e d an i n c r e a s e i n FEV , and 6 i n d i v i d u a l s i n c r e a s e d 1.0 i n %MMEFR. F o l l o w i n g c o n t i n u o u s warm-up, 3 s u b j e c t s i m p r o v e d i n %FVC, whereas o n l y 2 s u b j e c t s i m p r o v e d f o l l o w i n g t h e i n t e r v a l warm-up. P o s t - e x e r c i s e b r o n c h o d i l a t i o n has been s u g g e s t e d by G o d f r e y (1975) as b e i n g c a u s e d by an i n c r e a s e i n s y m p a t h e t i c d r i v e d u r i n g e x e r c i s e . I t can be c o n c l u d e d f r o m t h e above i n f o r m a t i o n t h a t a 15 min u t e c o n t i n u o u s warm-up a t an i n t e n s i t y e q u i v a l e n t t o 60% VO max and an i n t e r v a l warm-up c o n s i s t i n g o f 8 x 30 s e c o n d 2 s p r i n t s ( w i t h 1.5 m i n u t e s r e s t between s p r i n t s ) a t an i n t e n s i t y e q u i v a l e n t t o 100% V0 max w i l l n o t i n d u c e s i g n i f i c a n t p o s t -2 e x e r c i s e b r o n c h o c o n s t r i c t i o n . These r e s u l t s c o i n c i d e w i t h p r e v i o u s i n v e s t i g a t i o n s on t h e i n t e n s i t y and d u r a t i o n of e x e r c i s e r e q u i r e d f o r i n d u c i n g p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n ( F i t c h and G o d f r e y , 1976; M o r t o n , 1981; A n d e r s o n e t a l , 1 9 72). The e f f e c t of warm-up on p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n has been q u e s t i o n a b l e i n t h e p a s t . T h i s s t u d y , however, r e v e a l e d t h a t d u r i n g t h e c o n t i n u o u s warm-up c o n d i t i o n , p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n was s i g n i f i c a n t l y l e s s t h a n i f no warm-up 22 t o o k p l a c e . A l l i n d i v i d u a l s d e m o n s t r a t e d a d e c r e a s e i n %FEV , 1.0 %MMEFR and % F V C . D u r i n g t h e c o n t i n u o u s warm-up t h e mean changes f o r %FEV , %MMEFR, and %FVC were 16.7, 30.2, and 10.7, 1.0 r e s p e c t i v e l y . The means f o r t h e c o n t r o l were 34.6, 50.0, and 30.0. The mean d i f f e r e n c e between t h e s e c o n d i t i o n s a r e 17.3, 20.2, and 20.7, r e s p e c t i v e l y . In a d d i t i o n , 6 of t h e 12 s u b j e c t s c o n s t r i c t e d l e s s t h a n 15% f o l l o w i n g t h e warm-up c o n d i t i o n , w h i c h does not s a t i s f y t h e c r i t e r i a f o r EIA. T h i s s u g g e s t s t h a t , i n some i n d i v i d u a l s w i t h e x e r c i s e - i n d u c e d asthma, 15 m i n u t e s of c o n t i n u o u s r u n n i n g p r i o r t o e x e r c i s e w i l l s i g n i f i c a n t l y d e c r e a s e or p r e v e n t p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n . An i n t e r v a l warm-up p e r i o d a p p e a r e d t o have no s i g n i f i c a n t e f f e c t on p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n . E l e v e n s u b j e c t s d e m o n s t r a t e d g r e a t e r t h a n 15% c o n s t r i c t i o n f r o m b a s e l i n e v a l u e s . However, 9 i n d i v i d u a l s e x h i b i t e d a lo w e r %FEV and %MMEFR, 1.0 compared w i t h t h e no warm-up c o n d i t i o n , 2 i n d i v i d u a l s showed no change and ' one i n c r e a s e d b r o n c h o c o n s t r i c t i o n by 3%. T h i s i n c r e a s e d b r o n c h o c o n s t r i c t i o n may have r e s u l t e d from t h e p r e s e n c e o f an u n c o n t r o l l e d s t i m u l u s ( e n v i r o n m e n t a l s t r e s s or f o o d a l l e r g y ) . The mean d e c r e a s e i n %FEV , %MMEFR, and %FVC, 1.0 between t h e i n t e r v a l and no warm-up c o n d i t i o n s were 5.1, 6.6, and 9.0, r e s p e c t i v e l y . No s i g n i f i c a n t d i f f e r e n c e was d e t e c t e d between t h e c o n t i n u o u s and i n t e r v a l warm-ups. However, a l l i n d i v i d u a l s d e m o n s t r a t e d l o w e r %FEV , %MMEFR, and %FVC, i n d i c a t i n g l e s s 1.0 c o n s t r i c t i o n , f o l l o w i n g t h e c o n t i n u o u s warm-up i n t e r v e n t i o n . The mean d i f f e r e n c e s between t h e s e c o n d i t i o n s were: %FEV =13.0; 1.0 %MMEFR=13.2; and'%FVC=10.3. I t i s s u g g e s t e d t h a t w i t h a l a r g e r 23 sample s i z e , s i g n i f i c a n c e may have r e s u l t e d , between t h e c o n t i n u o u s warm-up and i n t e r v a l warm-up c o n d i t i o n s . Environmental c o n d i t i o n s have been s u g g e s t e d by many i n v e s t i g a t o r s ( D e a l e t a l , 1979; S t r a u s s e t a l , 1977; McFadden, 1983) t o be r e s p o n s i b l e f o r t h e d e g r e e o f a i r w a y c o n s t r i c t i o n . I t has been r e p o r t e d t h a t l o w e r i n s p i r a t o r y a i r t e m p e r a t u r e , l o w e r i n s p i r a t o r y water c o n t e n t , or bo t h w i l l s i g n i f i c a n t l y i n c r e a s e p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n . In a d d i t i o n , a h i g h i n s p i r a t o r y w a ter c o n t e n t and a h i g h room t e m p e r a t u r e w i l l d e c r e a s e t h e d e g r e e o f p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n . I t can t h e r e f o r e be c o n c l u d e d t h a t i f e n v i r o m e n t a l c o n d i t i o n s a r e h e l d c o n s t a n t , t h e r e p r o d u c i b i l i t y of EIA i n c r e a s e s ( D e a l e t a l , 1979; S t r a u s s e t a l , 1 9 78). In a d d i t i o n , an i n c r e a s e i n RHL w i l l i n c r e a s e p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n ( S t r a u s s e t a l , 1 9 77). In t h i s s t u d y , no s i g n i f i c a n t d i f f e r e n c e s i n room t e m p e r a t u r e , r e l a t i v e h u m i d i t y , ambient p r e s s u r e , i n s p i r e d water c o n t e n t , or RHL were d e t e c t e d between t h e 3 c o n d i t i o n s . The o n l y d i f f e r e n c e i n t h e t e s t i n g s e s s i o n s w hich may a c c o u n t f o r t h e r e s u l t s , i s t h e t r e a t m e n t i n t e r v e n t i o n . Thus, RHL does not e x p l a i n t h e d i f f e r e n c e i n a i r w a y r e a c t i v i t y . I t i s t h e r e f o r e s p e c u l a t e d t h a t c o n t i n u o u s warm-up i n f l u e n c e d t h e t r a n s l a t i o n a l e v e n t l e a d i n g t o p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n , and an e v a l u a t i o n of t h e p r o p o s e d mechanisms i s f u r t h e r w a r r a n t e d . The t h r e e mechanisms p o s t u l a t e d f o r t h i s phenomenum a r e a 24 d e s e n s i t i z a t i o n of the a i r w a y smooth m u s c l e t o t h e mast c e l l m e d i a t o r s , an i n h i b i t i o n ( o f su c h m e d i a t o r s as SRS-A or ECF-A) due t o e l e v a t e d e p i n e p h r i n e l e v e l s and t h e d e p l e t i o n of mast c e l l m e d i a t o r s ( S i l b e r e t a l , 1985; E g g l e s t o n , 1 9 8 6 ) . I t i s u n l i k e l y t h a t d e s e n s i t i z a t i o n of t h e smooth m u s c l e c e l l s o r t h a t e l e v a t e d e p i n e p h r i n e l e v e l s r e d u c e b r o n c h o c o n s t r i c t i o n d i f f e r e n t l y under each c o n d i t i o n . I f t h e s e mechanisms a r e t h e c a u s e of p o s t -e x e r c i s e b r o n c h o c o n s t r i c t i o n , t h e change i n b r o n c h o - c o n s t r i c t i o n would be e x p e c t e d t o be e q u a l under a l l t r e a t m e n t s . D e p l e t i o n of mast c e l l m e d i a t o r s t o r e s i s t h e most w i d e l y a c c e p t e d h y p o t h e s i s f o r p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n ( G o d f r e y , 1975; D e a l e t a l , 1979b). G o d f r e y (1975) t h e o r i z e s t h a t warm-up c a u s e s a g r a d u a l d i s c h a r g e of t h e mast c e l l m e d i a t o r s , and a time f o r r e p l e n i s h m e n t i s r e q u i r e d . I f e x e r c i s e resumes i m m e d i a t e l y f o l l o w i n g warm-up, t h e d e p l e t e d m e d i a t o r s t o r e s w i l l have a l i m i t e d e f f e c t on t h e smooth m u s c l e c e l l s . At t h e o n s e t of p h y s i c a l e x e r c i s e , v e n t i l a t i o n i n c r e a s e s and t h u s i n c r e a s e s RHL ( E g g l e s t o n , 1 9 86). An i n c r e a s e i n RHL i s h y p o t h e s i z e d t o i n t i a t e t h e l i b e r a t i o n of mast c e l l m e d i a t o r s w h i c h a c t d i r e c t l y on b r o n c h i a l smooth m u s c l e c e l l s ( D e a l e t a l , 1979b; S t r a u s s e t a l , 1978; McFadden, 1 9 8 3 ) . I n t h i s s t u d y , t h e f o l l o w i n g e x p l a n a t i o n has been s p e c u l a t e d . At t h e o n s e t o f warm-up, RHL i n c r e a s e s and t h e l i b e r a t i o n o f mast c e l l m e d i a t o r s o c c u r s . S i n c e RHL i s f a i r l y low d u r i n g t h e c o n t i n u o u s warm-up a t 60% VO max, g r a d u a l m e d i a t o r r e l e a s e c a u s i n g a d e p l e t i o n o f 2 s t o r e s o c c u r r e d . F i f t e e n m i n u t e s of slow m e d i a t o r r e l e a s e may 25 have c a u s e d a s u b s t a n t i a l d e c r e a s e i n the mast c e l l m e d i a t o r s t o r e s . T h i s p o s s i b l y l e d t o a s i g n i f i c a n t d e c r e a s e i n p o s t -e x e r c i s e b r o n c h o c o n s t r i c t i o n , f o l l o w i n g t h e c o n t i n u o u s warm-up, be c a u s e o f the l i m i t e d q u a n t i t y of m e d i a t o r s a c t i n g on t h e b r o n c h i o l a r m u s c l e c e l l s . D u r i n g the i n t e r v a l warm-up, 8 x 30 s e c o n d s p r i n t s ( t o t a l l i n g 4 m i n u t e s of a c t i v i t y ) d i d not c a u s e a • g r a d u a l d e p l e t i o n b ecause of the r e s t p e r i o d s between s p r i n t s . I t I s s p e c u l a t e d ,however, t h a t some r e l e a s e may have o c c u r r e d t o r e s u l t i n t h e s m a l l o b s e r v e d d e c r e a s e s i n %FEV and %MMEFR i n 1.0 each i n d i v i d u a l . S e v e r a l a n e c d o t a l r e p o r t s s u g g e s t i n g warm-up p r i o r t o e x e r c i s e d e c r e a s e s p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n a g r e e w i t h our f i n d i n g s . U n f o r t u n a t e l y , warm-up s p e c i f i c i t y has not been l o o k e d a t i n g r e a t d e t a i l : w i t h t h e e x c e p t i o n of 2 s t u d i e s , t h e i n t e n s i t y and d u r a t i o n of warm-up has not been c o n t r o l l e d . M o r t o n and c o l l e a g u e s (1981) l i m i t e d t h e i r warm-up t o 3 m i n u t e s a t an i n t e n s i t y e q u i v a l e n t t o 60% VO max. No s i g n i f i c a n t 2 d i f f e r e n c e i n p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n was d e t e c t e d , however, i t was s u g g e s t e d t h a t i n c r e a s i n g t h e d u r a t i o n may r e s u l t i n s i g n i f i c a n c e ( M o r t o n e t a l , 1 9 81). I t can t h e r e f o r e be c o n s i d e r e d , t h a t a l o n g e r d u r a t i o n of c o n t i n u o u s warm-up i s r e q u i r e d i n o r d e r t o c a u s e a s u b s t a n t i a l d e c r e a s e i n mast c e l l m e d i a t o r s t o r e s , and t h u s d e c r e a s e the d e g r e e of a i r w a y c o n s t r i c t i o n . S c h n a l l and Landau (1980) o b s e r v e d a d e c r e a s e i n p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n w i t h 7 x 30 s e c o n d s p r i n t s (2.5 2 6 m i n u t e s between s p i n t s ) . T h e s e r e s u l t s c o i n c i d e w i t h t h i s s t u d y , however, s t a t i s t i c a l a n a l y s i s on our r e s u l t s showed non-s i g n i f i c a n c e . CONCLUSION A c o n t i n u o u s warm-up o f 15 m i n u t e s d u r a t i o n a t an i n t e n s i t y e q u i v a l e n t t o 60% VO max s i g n i f i c a n t l y d e c r e a s e s p o s t - e x e r c i s e 2 b r o n c h o c o n s t r i c t i o n i n m o d e r a t e l y t r a i n e d i n d i v i d u a l s w i t h e x e r c i s e - i n d u c e d asthma. An i n t e r v a l warm-up i n v o l v i n g 8 x 30 se c o n d s p r i n t s ( w i t h 1.5 m i n u t e s r e s t between s p r i n t s ) does not s i g n i f i c a n t l y d e c r e a s e p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n , a l t h o u g h e a c h i n d i v i d u a l d e m o n s t r a t e d a d e c r e a s e . E n v i r o n m e n t a l c o n d i t i o n s had no s i g n i f i c a n t change o v e r t h e t h r e e c o n d i t i o n s , r e g a r d l e s s o f t h e s i g n i f i c a n c e i n p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n . 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R e s p i r a t o r y h e a t l o s s and water e x c h a n g e : p h y s i o l o g i c a l and c l i n i c a l i m p l i c a t i o n s . J . A p p l . P h y s i o l . 54:331-336. M c K e n z i e DC, Rhodes EC, S t i r l i n g DR, W i l e y J P , Dunwoody DW, F i l s i n g e r IB, Jang I , S t e v e n s A ( 1 9 8 3 ) . S a l b u t a m o l and t r e a d m i l l p e r f o r m a n c e i n n o n - a t o p i c a t h l e t e s . 1 5 ( 6 ) : 5 2 0 - 5 2 2 . M a r l e y WP. ( 1 9 7 7 ) . Asthma and E x e r c i s e ; A R eview. Amer. C o r r . T h e r . J . 3 1 ( 4 ) : 9 5 - 1 0 2 . Monks AW. ( 1 9 8 0 ) . E x e r c i s e - i n d u c e d Asthma — The C h i l d and P h y s i c a l E d u c a t i o n . Asthma i n C h i l d r e n ( E d . Kuzemko JA) E n g l a n d : 9 7 . M o r t o n AR, F i t c h KD, D a v i s T ( 1 9 7 9 ) . The e f f e c t o f 'warm-up' on e x e r c i s e - i n d u c e d asthma. A n n a l s o f a l l e r g y 42:257-260. M o r t o n AR, F i t c h KD, Hahn AG. ( 1 9 8 1 ) . P h y s i c a l A c t i v i t y and t h e A s t h m a t i c . P h y s i c i a n a n d . S p o r t s M e d i c i n e . 9 ( 3 ) : 5 1 - 6 4 . Naimark A, Wasserman K, M c l l r o y MB ( 1 9 6 4 ) . C o n t i n u o u s measurement of v e n t i l a t i o n a l t e r a t i o n s i n end t i d a l C02 t e n s i o n on f l o w r e s i s t a n c e . J . A p p l . P h y s i o l . 19:745. Rees HA, (1966) B l o o d g a s e s i n asthma. P r o c . T h o r a c . S o c . 21:485 Rhodes EC, W i l e y J P , Dunwoody DW ( 1 9 8 1 ) . Data a c q u i s i t i o n s y s t e m f o r a s s e s s i n g m e t a b o l i c and r e s p i r a t o r y f u n c t i o n d u r i n g e x e r c i s e . Med. S c i . S p o r t s E x e r . 13:101 ( A b s t r a c t ) . S c h n a l l RP, Landau L I . ( 1 9 8 0 ) . P r o t e c t i v e e f f e c t s of r e p e a t e d s h o r t s p r i n t s i n e x e r c i s e - i n d u c e d asthma. T h o r a x . 35:828-832. S h e p a r d R J , A l l e n C, Renade AJS, D a v i e s CTM, D i P r a m p e r o PE, Hedman R, Merriman J E , Myhre K, Simmons R (1968) S t a n d a r d i z a t i o n o f submaximal e x e r c i s e t e s t s . B u l l . WHO 38:765-766. 31 S i l b e r G, N a c l e r i o P, E g g l e s t o n P, Pr o u d D, T o g i a s A, L i g h t e n s t e i n LM ( 1 9 8 5 ) . In v i v o r e l e a s e o f h i s t a m i n e by h y p e r o s m o l a r s t i m u l i ( A b s t r a c t ) . J . A l l e r g y C l i n . Immunol. 75:285. S i l v e r m a n M, A n d e r s o n SD (1972) S t a n d a r d i z a t i o n o f e x e r c i s e t e s t s i n a s t h m a t i c c h i l d r e n . A r c h . D i s . C h i l d . 47:882. S l y RM (1971) E f f e c t of c r o m o l y n sodium on e x e r c i s e - i n d u c e d a i r w a y o b s t r u c t i o n i n a s t h m a t i c c h i l d r e n . A n n a l s of A l l e r g y . 29:362 S l y RM ( 1 9 7 6 ) . E x e r c i s e - I n d u c e d Asthma. B r o n c h i a l Asthma: M e c h n i c s and T h e r a p e u t i c s . by EB Weiss and MS S e g a l ; L i t t l e Brown and Co. S l y RM (1986) H i s t o r y of e x e r c i s e - i n d u c e d asthma. M e d i c i n e and S c i e n c e i n S p o r t s and E x e r c i s e . 1 8 ( 3 ) : 3 1 4 - 3 1 7 . Sou h r a d a M, S o u h r a d a J F (1981) The d i r e c t e f f e c t of t e m p e r a t u r e on a i r w a y smooth m u s c l e . Resp. P h y s i o l . 44:311-323. S t e a r n s DR, McFadden ER J r , B r e s l i n F J , Ingram JR ( 1 9 8 1 ) . R e a n a l y s i s o f t h e r e f r a c t o r y p e r i o d i n e x e r t i o n a l a sthma. J . A p p l . P h y s i o l . 50:503-508. S t i r l i n g DR, C o t t o n DJ, Graham BL, Hodgson WC, C o c k c r o f t DW, Dolman JA ( 1 9 8 3 ) . C h a r a c t e r i s t i c s o f a i r w a y t o n e d u r i n g e x e r c i s e i n p a t i e n t s w i t h asthma. E x e r c i s e i n Asthma. A m e r i c a n P h y s i o l o g i c a l S o c i e t y . 934-942. S t r a u s s RH, .McFadden ER J r , Ingram RH J r , J a g g e r J J . ( 1 9 7 7 ) . Enhancement of e x e r c i s e - i n d u c e d asthma by c o l d a i r . N. E n g l . J . Med. 297:743-747. S t r a u s s RH, McFadden ER, Ingram RH J r , D e a l EC J r , J a g g e r J J . ( 1 9 7 8 ) . I n f l u e n c e o f h e a t and h u m i d i t y on t h e a i r w a y o b s t r u c t i o n i n d u c e d by e x e r c i s e i n asthma. J . C l i n . I n v e s t . 61:318-321. T a i E, Reed J ( 1 9 6 7 ) . B l o o d gas t e n s i o n s i n b r o n c h i a l asthma. L a n c e t , i : 6 4 4 . V a r v a J , Macek M, S p i c a k V (1969) La c a p a c i t e de t r a v a i l c h e z l e s e n f a n t s a s t h m a t i q u e s . Rev. Ped. 1:3 ( E n g . A b s t r a c t ) . V a s s a l l o CL, Gee J B L , Domm BM ( 1 9 7 2 ) . E x e r c i s e - i n d u c e d asthma. Am. Rev. Resp. D i s . 105:42. Voy RO ( 1 9 8 6 ) . The U.S. O l y m p i c Committee e x p e r i e n c e w i t h e x e r c i s e - i n d u c e d b r o n c h o s p a s m . M e d i c i n e and S c i e n c e i n S p o r t s and E x e r c i s e . 1 8 ( 3 ) : 3 2 8 - 3 3 0 . 32 Wasserman K, Van Kessek AL, B u r t o n GG ( 1 9 6 7 ) . I n t e r a c t i o n of P h y s i o l o g i c a l Mechanisms D u r i n g E x e r c i s e . J . A p p l . P h y s i o l . 22:71-85. West JB, D o l l e r y CT ( 1 9 6 0 ) . D i s t r i b u t i o n o f b l o o d f l o w and v e n t i l a t i o n p e r f u s i o n r a t i o i n l u n g s , measured w i t h r a d i o -a c t i v e CO . J . A p p l . P h y s i o l . 15:405. 2 Whipp B J , Wasserman K ( 1 9 6 9 ) . A l v e o l a r - a r t e r i a l gas t e n s i o n d i f f e r e n c e s d u r i n g g r a d e d e x e r c i s e . J . A p p l . P h y s i o l . 27:361. W i l l i s T ( 1 6 7 9 ) . P h a r m a c e u t i c a R a t i o n a l e s , P a r t 2. London.: D r i n g , H a r p e r and L e i g h . 33 APPENDICES 34 APPENDIX A REVIEW OF LITERATURE INTRODUCTION: B r o n c h i a l asthma i s t h e most common r e s p i r a t o r y d i s o r d e r i n N o r t h A m e r i c a and i s p r e s e n t i n o v e r 8 m i l l i o n i n d i v i d u a l s ( M a r l e y , 1 9 77). Seven p e r c e n t o f t h e e n t i r e p o p u l a t i o n have asthma and 15-20% e x p e r i e n c e a l l e r g i e s . N i n e t y - f i v e p e r c e n t of t h e s e a t o p i c , and 3-4% o f n o n - a t o p i c i n d i v i d u a l s ( G o d f r e y , 1975; Voy, 1986) e x p e r i e n c e b r o n c h o s p a s m 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 . T h i s p h y s i c a l c o n d i t i o n i n w h i c h a i r w a y r e s i s t a n c e i n c r e a s e s as a r e s u l t o f e x e r c i s e i s r e f e r r e d t o as e x e r c i s e - i n d u c e d asthma ( E I A ) or e x e r c i s e - i n d u c e d b r o n c h o s p a s m ( E I B ) . Many i n d i v i d u a l s w i t h t h i s d i s o r d e r a v o i d s p o r t s p a r t i c i p a t i o n . However, o t h e r s have engaged i n a v a r i e t y of a t h l e t i c s and many have a c h i e v e d e l i t e p e r f o r m a n c e s . At t h e 1984 Summer O l y m p i c Games, 67 of 597 a t h l e t e s had EIA. These i n d i v i d u a l s p a r t i c i p a t e d i n 29 d i f f e r e n t O l y m p i c e v e n t s . F o r t y -one o f t h e 67 a t h l e t e s a c h i e v e d medals (15 g o l d ; 21 s i l v e r ; and 5 b r o n z e ) a t t h e games (Voy, 1 9 86). T w e n t y - e i g h t of t h e s e a t h l e t e s were f e m a l e and t h i r t y - e i g h t were male. Asthma i s more p r e v e l e n t i n m ales compared w i t h f e m a l e s d u r i n g c h i l d h o o d w i t h a r a t i o of 2:1 (Voy, 1986; F i t c h , 1 9 8 4). However, by 30 y e a r s of age t h i s r a t i o becomes e q u a l (Voy, 1 9 8 6 ) . 35 HISTORICAL REVIEW: As e a r l y as t h e s e c o n d c e n t u r y A.D., A r e t a e u s o f C a p p a d o c i a w r o t e ' I f from r u n n i n g , g y m n a s t i c e x e r c i s e s , o r any o t h e r work, the b r e a t h i n g becomes d i f f i c u l t , i t i s c a l l e d Asthma...' (Adams, 1 9 6 9 ) . D u r i n g th e s e v e n t e e n t h c e n t u r y , Thomas W i l l i s (1679) o b s e r v e d t h a t a s t h m a t i c a t t a c k s c o u l d be p r o v o k e d by p h y s i c a l e x e r c i s e ( S l y , 1976). At t h e t u r n of t h e c e n t u r y , S i r J . F l o y e r (1698) not o n l y r e c o r d e d t h a t an a t t a c k of asthma c o u l d be p r o v o k e d by e x e r c i s e but n o t e d t h a t d i f f e r e n t f orms of e x e r c i s e d i f f e r e d i n the d e g r e e o f a t t a c k ( A n d e r s o n e t a l , 1975; S l y , 1 9 8 6). I t was g e n e r a l l y a g r e e d t h r o u g h t h e s e v e n t e e n t h and e i g h t e e n t h c e n t u r i e s ( W i l l i s , 1679; F l o y e r , 1698; C u l l e n , 1784) t h a t asthma was due t o n a r r o w i n g of t h e b r o n c h i . D u r i n g th e n i n e t e e n t h c e n t u r y t h e r e l a t i o n s h i p between e x e r c i s e and asthma was l o o k e d a t by o n l y 2 i n v e s t i g a t o r s . I t has been r e p o r t e d t h a t i n 1868 S a l t e r o b s e r v e d i n 54 of 223 p a t i e n t s ' e x e r t i o n was an e x c i t i n g c a u s e of symptoms' ( A n d e r s o n e t a l , 1975), and t h a t ' r a p i d p a s s a g e of f r e s h and c o l d a i r o v e r t h e b r o n c h i a l mucus membrane' may a c t d i r e c t l y on t h e a i r w a y s or by i r r i t a t i n g t h e n e r v o u s s y s t e m ( S l y , 1 9 86). In 1873 Thorowgood commented t h a t an a t t a c k c o u l d be p r e v e n t e d by m i l d e x e r c i s e i n a s t h m a t i c s and t h e r e f o r e t h e e f f e c t o f e x e r c i s e c o u l d be b e n e f i c i a l t o a s t h m a t i c i n d i v i d u a l s ( A n d e r s o n e t a l , 1 9 75). The f i r s t o b j e c t i v e r e s e a r c h i n e x e r c i s e and asthma i s c r e d i t e d t o H e r x h e i m e r i n 1946. By m e a s u r i n g and r e c o r d i n g c h a n g e s i n v i t a l c a p a c i t y , i n 6 a s t h m a t i c i n d i v i d u a l s , b e f o r e and 36 a f t e r s h o r t terra r u n n i n g and c y c l i n g e x e r c i s e s , H e r x h e i m e r c o n c l u d e d t h a t t h e h y p e r v e n t i l a t i o n o f e x e r c i s e was r e s p o n s i b l e f o r t h e f a l l i n v i t a l c a p a c i t y w hich f o l l o w e d e x e r c i s e ( A n d e r s o n , e t a l , 1975). In a d d i t i o n , he b e l i e v e d t h a t hypocapnea and r e s p i r a t o r y a l k a l o s i s was a l s o a p r o b a b l e c a u s e of EIA ( S l y , 1986). T h i s h y p o t h e s i s was l a t e r d i s p r o v e d . In 1952 P e a r s o n r e c o r d e d t h a t i n some a s t h m a t i c i n d i v i d u a l s , a d e c r e a s e i n v i t a l c a p a c i t y o c c u r r e d f o l l o w i n g e x e r c i s e ; w h i l e i n o t h e r s 2-second v i t a l c a p a c i t y i m p roved i m m e d i a t e l y a f t e r e x e r c i s e ( S l y , 1976; A n d e r s o n e t a l , .1975). F o r t h e n e x t t e n y e a r s s t u d i e s on t h e e f f e c t s of p h y s i c a l e x e r c i s e on a s t h m a t i c i n d i v i d u a l s l e d t o many c o n t r o v e r s i a l f i n d i n g s : d e c r e a s e d a i r w a y o b s t r u c t i o n , i n c r e a s e d a i r w a y o b s t r u c t i o n , or b o t h ( S l y , 1 9 76). L a t e r i t was f o u n d t h a t t h e s e c o n f l i c t i n g r e p o r t s were c a u s e d by a d d i t i o n a l f a c t o r s a s s o c i a t e d w i t h i n d u c i n g p o s t e x e r c i s e - b r o n c h o c o n s t r i c t i o n . I t was not u n t i l J o n e s and c o l l e a g u e s (1963) i n v e s t i g a t e d t h e e f f e c t of b r i e f and p r o l o n g e d e x e r c i s e d u r i n g r u n n i n g , t h a t was shown t h a t 2 m i n u t e s o f b r i e f r u n n i n g c a u s e d b r o n c h o d i l a t i o n (an i n c r e a s e i n FEV1.0) whereas p r o l o n g e d e x e r c i s e (8-12 m i n u t e s ) c a u s e d a s i g n i f i c a n t d e c r e a s e i n FEV ( A n d e r s o n e t a l , 1975; S l y , 19 8 6 ) . 1.0 J o n e s e t a l , (1963) f o u n d t h a t t h e b i c y c l e e r g o m e t e r d i d not c a u s e as g r e a t of a r e d u c t i o n i n FEV and t h a t f r e q u e n t 1.0 i n t e r r u p t i o n of e x e r c i s e ( t o make measurements) may d e c r e a s e t h e d e g r e e o f b r o n c h o c o n s t r i c t i o n and t h e r e f o r e s h o u l d be a v o i d e d d u r i n g t e s t i n g s e s s i o n s ( A n d e r s o n e t a l , 1 9 7 5 ) . 37 From t h i s p o i n t on, r e s e a r c h i n e x e r c i s e and asthma has become w i d e s p r e a d . I n v e s t i g a t i o n s i n t o t h e methods of measurements and t e s t i n g , f a c t o r s a f f e c t i n g t h e magni t u d e of r e s p o n s e , p a t h o p h y s i o l o g y , and t h e r a p e u t i c i m p l i c a t i o n s a r e c o n t i n u a l l y b e i n g u n d e r t a k e n . CLINICAL PRESENTATION: Common c l i n i c a l s i g n s i n d i c a t i v e o f EIA i n c l u d e e p i s o d e s of w h e e z i n g , d y s p n e a , c o u g h i n g , c h e s t t i g h t n e s s , i n c r e a s e d n a s a l s e c r e t i o n s , and sputum p r o d u c t i o n . These symptoms a r e b r o u g h t a b o u t by l o c a l i z e d edema i n t h e w a l l s of t h e s m a l l b r o n c h i o l e s , s e c r e t i o n of t h i c k mucus i n t o t h e b r o n c h i o l a r lumens, a n d / o r spasm o f t h e b r o n c h i o l a r smooth m u s c l e ( G u y t o n , 1982). METHODS OF TESTING: In t h e d i a g n o s i s of e x e r c i s e - i n d u c e d asthma, a t h l e t e s w i t h a h i s t o r y of c h r o n i c c h e s t symptoms, a l l e r g i e s , and c h r o n i c cough s h o u l d undergo l a b o r a t o r y t e s t i n g to a s s e s s t h e p r e s e n c e and d e g r e e o f p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n . B r o n c h i a l r e s p o n s i v e n e s s t o e x e r c i s e i s h i g h l y c o r r e l a t e d w i t h the a d m i n i s t r a t i o n of h i s t a m i n e or m e t h a c h o l i n e ( A n d e r t o n e t a l , 1979; K a t z , 1 9 83). T h e r e f o r e , h i s t a m i n e or m e t h a c h o l i n e c h a l l e n g e s a r e o f t e n used i n t h e d i a g n o s i s o f E I A . However, t h e most a c c u r a t e method of a s s e s s i n g p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i s by a s t a n d a r d i z e d e x e r c i s e c h a l l e n g e t e s t ( K a t z , 1983; E g g l e s t o n , 1 9 84). P r i o r to an e x e r c i s e c h a l l e n g e t e s t , t h e i n d i v i d u a l s ' 38 pulmonary f u n c t i o n measures s h o u l d be w i t h i n 80% of p r e d i c t e d v a l u e s ( E g g l e s t o n , 1 9 84). I n d i v i d u a l s must w i t h o l d m e d i c a t i o n 8-12 h o u r s p r i o r t o t e s t i n g s e s s i o n s and not p a r t i c i p a t e i n any p h y s i c a l a c t i v i t y or i n j e s t c a f f e i n e 4 h o u r s p r i o r t o t h e t e s t ( E g g l e s t o n , 1984). A s t a n d a r d i z e d e x e r c i s e c h a l l e n g e t e s t i s p e r f o r m e d on a t r e a d m i l l or c y c l e e r g o m e t e r , however, the l a t e r of t h e s e a l l o w s t h e a t h l e t e t o e x e r c i s e more v i g o r o u s l y and a c h i e v e a h i g h e r l e v e l of c a r d i o - p u l m o n a r y s t r e s s w i t h o u t l e g d i s c o m f o r t ( E g g l e s t o n , 1 9 84). The d u r a t i o n o f t h e e x e r c i s e i s 6-8 m i n u t e s a t an i n t e n s i t y w hich m a i n t a i n s th e h e a r t r a t e a t 90% o f maximal v a l v e . E l e c t r o c a r d i o g r a p h i c m o n i t o r i n g , w i t h a c o n t i n u o u s s t r i p c h a r t , a n d / o r c o n t i n u o u s v e n t i l a t o r y a s s e s s m e n t d u r i n g t h e t e s t i s n e c e s s a r y . M i n u t e v e n t i l a t i o n w i l l p r o v i d e a more d i r e c t measurement of t h e r e l a v e n t s t r e s s s i n c e h y p e r v e n t i l a t i o n can i n i t i a t e EIA. T h e r e f o r e , c o n t i n u o u s v e n t i l a t o r y m o n i t o r i n g i s a b e t t e r a s s e s s m e n t of t h e work i n t e n s i t y ( E g g l e s t o n , 1 9 8 4 ) . LUNG MECHANICS AND BLOOD GAS CHANGES: Ai r w a y r e s i s t a n c e i s most a c c u r a t e l y d e t e r m i n e d by the c hanges i n peak e x p i r a t o r y f l o w r a t e s (PEFR: A n d e r s o n e t a l , 1 9 7 5 ) . F o r c e d e x p i r a t o r y volume i n one s e c o n d i s i n d i c a t i v e of l a r g e a i r w a y r e s i s t a n c e and maximal m i d - e x p i r a t o r y f l o w r a t e ( 2 5 -75% FEV ) i s i n d i c a t i v e of s m a l l a i r w a y r e s i s t a n c e . Peak 1.0 e x p i r a t o r y f l o w r a t e (PEFR) i s o f t e n used i n t h e d e t e r m i n a t i o n of b r o n c h o c o n s t r i c t i o n , however, r e s u l t s have been more v a r i a b l e 39 which may r e f l e c t an i n d i v i d u a l ' s e f f o r t o f r e s p o n s e d u r i n g t h e t e s t ( K a t z , 1 9 8 3 ) . A d e c r e a s e i n F E V from b a s e l i n e v a l u e s of 1 5 - 2 0 % i s 1 . 0 s i g n i f i c a n t f o r m i l d b r o n chospasm, 2 0 - 3 0 % f o r m i l d - m o d e r a t e b r o nchospasm, and g r e a t e r t h a n 30% i s i n d i c a t i v e f o r s e v e r e bronchospasm ( K a t z , 1 9 8 3 ) . R e s e a r c h has shown t h a t 92% of a h e a l t h y p o p u l a t i o n have a f a l l i n F E V 1 . 0 o f l e s s t h a n 1 0 % , and 98% have a f a l l l e s s t h a n 15% f o l l o w i n g e x e r c i s e ( B u r r , 1 9 7 5 ) . A s t h m a t i c i n d i v i d u a l s , however, p r e s e n t a 2 0 - 6 0 % d e c r e a s e i n F E V , from b a s e l i n e v a l u e s , w i t h i n 1 0 m i n u t e s of c o m p l e t e d 1 . 0 e x e r c i s e ( K a t t a n , 1 9 8 3 ) . An a p p r o p r i a t e e x e r c i s e s t i m u l u s w i l l p r o v o k e a c h a r a c t e r i s t i c p h y s i o l o g i c a l r e s p o n s e i n an e x e r c i s e - i n d u c e d a s t h m a t i c , a l t h o u g h th e m a g n i t u d e o f r e s p o n s e may v a r y w i t h c l i n i c a l s t a t e ( G o d f r e y , 1 9 7 5 ; K a t z , 1 9 8 3 ; A n d e r s o n e t a l , 1 9 7 5 ) . D u r i n g th e i n i t i a l 4 m i n u t e s of a s i x - m i n u t e p e r i o d o f v i g o r o u s e x e r c i s e (> 80% maximum p r e d i c t e d h e a r t r a t e f o r age) a d e f i n i t e b r o n c h o d i l a t i o n of t h e a i r w a y s o c c u r s p r o d u c i n g an i n c r e a s e i n pulmonary f u n c t i o n measures ( P E F R , F E V , and M M E F R : 1 . 0 K a t z , 1 9 8 3 ; A n d e r s o n , 1 9 7 2 ; A n d e r s o n e t a l , 1 9 7 5 ; S l y , 1 9 7 6 ) . T h i s i s b e l i e v e d t o be c a u s e d by an i n c r e a s e i n s y m p a t h e t i c d r i v e d u r i n g e x e r c i s e ( G o d f r e y , 1 9 7 5 ) . A f t e r t h i s p o i n t , c o n s t r i c t i o n o f t h e a i r w a y s b e g i n and r e s u l t i n d e c r e a s i n g l u n g f u n c t i o n . At t h e c o m p l e t i o n of t h e 6 minute e x e r c i s e , b r o n c h o c o n s t r i c t i o n c o n t i n u e s , r e a c h i n g a peak a t 3 - 4 m i n u t e s p o s t e x e r c i s e i n c h i l d r e n and 4 - 6 m i n u t e s i n a d u l t s ( G o d f r e y , 1 9 7 5 ; K a t z , 1 9 8 3 ) . 40 The a i r w a y s t h e n b e g i n t o r e t u r n t o n o r m a l b a s e l i n e v a l u e s between 20-60 m i n u t e s . R e s e a r c h i n t o t h e gas t e n s i o n s of a r t e r i a l b l o o d d u r i n g e x e r c i s e i n a s t h m a t i c i n d i v i d u a l s has p r o d u c e d c o n t r o v e r s i a l r e p o r t s . V a r v a and c o l l e a g u e s (1969) has r e p o r t e d no change i n oxygen t e n s i o n , w h i l e K a t z and c o - w o r k e r s (1971) and A n d e r s o n (1972) r e p o r t e d an i n c r e a s e i n a r t e r i a l P02 i n t h e f i r s t few m i n u t e s of e x e r c i s e . These d i f f e r e n c e s may be a c c o u n t e d f o r by t h e e x e r c i s e t e c h n i q u e used ( A n d e r s o n e t a l , 1 9 7 5 ) . I n v e s t i g a t o r s ( N a i m a r k e t a l , 1964; Whipp and Wasserman, 1969) have f o u n d t h a t t h e r i s e i n a r t e r i a l P02 d u r i n g e x e r c i s e i n a s t h m a t i c s e x c e e d e d t h e a r t e r i a l P02 r i s e seen i n h e a l t h y i n d i v i d u a l s . T h i s may be e x p l a i n e d by a b e t t e r d i s t r i b u t i o n o f t h e v e n t i l a t i o n / p e r f u s i o n r a t i o i n t h e l u n g s d u r i n g e x e r c i s e (West and D o l l e r y , 1960). S i l v e r m a n and A n d e r s o n (1972) have shown a r t e r i a l pCO t o 2 d e c r e a s e d u r i n g e x e r c i s e w h i l e o t h e r r e p o r t s ( V a r v a e t a l , 1969; F i s h e r e t al', 1970; V a s a l l o e t a l , 1972) r e p o r t no c hange. D u r i n g e x e r c i s e , t h e h i g h e r b l o o d l a c t a t e l e v e l s t h a t have been r e p o r t e d i n a s t h m a t i c s a r e c o n s i s t e n t w i t h r e p o r t s i n n o r m a l s u b j e c t s (Wasserman, 1967; Hermansen and S a l t i n , 1 9 6 9). However, t h e r e have been r e p o r t s o f l a c t a t e v a l u e s t h a t a r e s i g n i f i c a n t l y g r e a t e r i n a s t h m a t i c s opposed t o h e a l t h y s u b j e c t s w o r k i n g a t t h e same oxygen c o n s u m p t i o n ( V a v r a e t a l , 1969; A n d e r s o n , 1 9 7 2 ) . These h i g h e r t h a n n o r m a l v a l u e s f o r b l o o d l a c t a t e a r e r e f l e c t i v e i n t h e l o w e r t h a n n o r m a l pH v a l u e s seen d u r i n g e x e r c i s e i n a s t h m a t i c s ( A n d e r s o n , 1972). 41 Upon c o m p l e t i o n of e x e r c i s e , i n i n d i v i d u a l s w i t h EIA, a r t e r i a l - o x y g e n t e n s i o n d e c r e a s e s ( A n d e r s o n , 1972; K a t z , 1983). T h i s c o r r e s p o n d s t o t h e a r t e r i a l hypoxaemia seen i n p a t i e n t s e x p e r i e n c i n g o t h e r forms of a c u t e asthma but i s a b s e n t i n h e a l t h y s u b j e c t s f o l l o w i n g e x e r c i s e ( R e e s , 1966; T a i and Reed, 1967; McFadden, 1983). F o l l o w i n g e x e r c i s e , a r t e r i a l pCO i n c r e a s e s i n r e l a t i o n t o 2 b r o n c h o c o n s t r i c t i o n . These v a l u e s a r e g r e a t e r t h a n would be seen i n h e a l t h y i n d i v i d u a l s ( A n d e r s o n , 1972). E g g l e s t o n (1986) r e p o r t s t h a t d u r i n g h y p e r v e n t i l a t i o n a r t e r i a l p02 i s m a i n t a i n e d , however, t i s s u e oxygen u t i l i z a t i o n i s l e s s e f f i c i e n t r e s u l t i n g i n m e t a b o l i c a c i d o s i s when w o r k i n g a t an i n t e n s i t y e q u a l or g r e a t e r t h a n 50% maximal oxygen c o n s u m p t i o n ( S h e p a r d e t a l , 1968). M e t a b o l i c a c i d o s i s may o c c u r f o r 15-30 m i n u t e s a f t e r e x e r c i s e , c a u s i n g t h e pH v a l u e s t o f a l l to low l e v e l s of 7.10-7.20 ( E g g l e s t o n , 1986). As a r e s u l t , t h e s e c h a n g es i n b l o o d g a s e s a s s o c i a t e d w i t h EIA, may d e c r e a s e an a t h l e t e s p e r f o r m a n c e . In a d d i t i o n , t h e r e have been r e p o r t s o f e l e v a t e d plasma h i s t a m i n e c o n c e n t r a t i o n s f o l l o w i n g e x e r c i s e i n s e v e r e a s t h m a t i c s (McFadden e t a l , 1 9 80). I n d i v i d u a l s w i t h m i l d EIA have shown s m a l l i n c r e a s e s i n h i s t a m i n e l e v e l s , and a s t h m a t i c s which f a i l t o b r o n c h o c o n s t r i c t f o l l o w i n g e x e r c i s e show l i t t l e or no change i n plasma h i s t a m i n e c o n c e n t r a t i o n s ( S l y , 1 9 76). PATHOPHYSIOLOGY OF EXERCISE-INDUCED ASTHMA: The p a t h o g e n e s i s of e x e r c i s e - i n d u c e d asthma i s not f u l l y u n d e r s t o o d d e s p i t e t h e numerous s t u d i e s . I t i s g e n e r a l l y a g r e e d hi t h a t t h e i n i t i a t i n g s t i m u l u s i s a p h y s i o l o g i c a l s t r e s s a c t i n g on t h e m u c o s a l l i n i n g o f the a i r w a y s ( E g g l e s t o n , 1986). The most w i d e l y a c c e p t e d p h y s i o l o g i c a l s t r e s s h y p o t h e s i z e d i s t h e c o o l i n g and d e h y d r a t i o n of t h e a i r w a y s ( D e a l e t a l , 1979b; S t r a u s s e t a l , 1978; G o d f r e y , 1975; E i s e n s t a d t , 1984; K a t z , 1983; A n d e r s o n e t a l , 1 9 7 9). T h i s i s c o n s i s t e n t w i t h t h e e a r l i e r r e p o r t s o f swimming (a warm-humid e n v i r o m e n t ) b e i n g l e s s a s t h m o g e n i c t h a n r u n n i n g ( c o o l - d r y e n v i r o m e n t ) . Chen and H o r t o n ( 1 9 7 7 ) , and S t r a u s s e t a l ( 1 9 7 8 ) , p r e v e n t e d p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n by a d m i n i s t e r i n g 100% s a t u r a t e d a i r a t body t e m p e r a t u r e to e x e r c i s i n g a s t h m a t i c s . I t has d e m o n s t r a t e d t h a t the magnitude of p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i s p r o p o r t i o n a l t o t h e h e a t exchange which o c c u r s w i t h i n t h e a i r w a y s , and i n v e r s e l y p r o p o r t i o n a t e t o t h e w ater c o n t e n t o f t h e i n s p i r e d a i r between t h e t e m p e r a t u r e s o f 25-37 °C ( S t r a u s s e t a l , 1978; D e a l e t a l , 1 9 7 9 c ) . The l e v e l of v e n t i l a t i o n has been s u g g e s t e d t o be t h e most i m p o r t a n t f a c t o r i n i n i t i a t i n g EIA ( E g g l e s t o n , 1986; D e a l e t a l , 1 979b). In d e t e r m i n i n g r e s p i r a t o r y h e a t l o s s , t h e f o l l o w i n g e q u a t i o n i s used : RHL = VE(HC ( T i - T e ) + HV (WCi-WCe)) where RHL i s t h e r e s p i r a t o r y h e a t exchange i n k c a l / m i n . ; ;,VE, m i n u t e v e n t i l a t i o n i n 1/min. ( B T P S ) ; HC, h e a t c a p a c i t y o f a i r = s p e c i f i c h e a t x d e n s i t y = 0.000304 k c a l / 1 p e r " C ; T i , i n s p i r e d a i r t e m p e r a t u r e i n "C; Te, e x p i r e d a i r t e m p e r a t u r e i n °C; HV, 'heat H 3 of v a p o r i z a t i o n of water = 0.58 k c a l / g ; WCi, water c o n t e n t o f t h e i n s p i r e d a i r i n mg w a t e r / 1 a i r ; WCe, water c o n t e n t o f e x p i r e d a i r i n mg water/1 a i r ( S t r a u s s e t a l , 1 977). From t h i s e q u a t i o n i t can be seen t h a t i f t h e l e v e l of v e n t i l a t i o n i s changed a t a c o n t r o l l e d t e m p e r a t u r e and h u m i d i t y , RHL w i l l change p r o p o r t i o n a l l y c a u s i n g a s i m i l a r d e g r e e of change i n b r o n c h o c o n s t r i c t i o n . E g g l e s t o n ( 1 9 8 6 ) , r e p o r t s l i t t l e change i n FEV a t low l e v e l s of v e n t i l a t i o n , w h i l e g r e a t e s t c h a n g es i n 1.0 pulmonary f u n c t i o n a r e seen when l e v e l s o f v e n t i l a t i o n a r e i n c r e a s e d and t h e water c o n t e n t of t h e i n s p i r e d a i r i s e l i m i n a t e d . F o r t h i s r e a s o n , s t u d i e s i n v e s t i g a t i n g h y p e r p n e a i n r e l a t i o n t o e x e r c i s e and a i r w a y c o n s t r i c t i o n have been c a r r i e d o u t . D e a l e t a l (1979b) l o o k e d a t the e f f e c t of h y p e r p n e a on a i r w a y c o n s t r i c t i o n by h a v i n g i n d i v i d u a l s h y p e r v e n t i l a t e under d i f f e r e n t a i r t e m p e r a t u r e s and s a t u r a t i o n l e v e l s . He c o n c l u d e s t h a t t h e major s t i m u l u s f o r EIA i s h e a t l o s s from t h e mucosa w i t h s u b s e q u e n t c o o l i n g p r e c i p i t a t e d by t h e h y p e r p n e a of e x e r c i s e and not the e x e r c i s e a l o n e . T h e r e has been some c o n f l i c t i n g e v i d e n c e i n r e l a t i o n t o t h e r e s p i r a t o r y h e a t l o s s h y p o t h e s i s . B r o n c h o c o n s t r i c t i o n s t i l l o c c u r e d i n some a s t h m a t i c s t h a t b r e a t h e d warm-humid a i r i n which RHL was n e g l i g i b l e ( A n d e r s o n e t a l , 1980; B a r - Y i s h a y e t a l , 1982). Twelve of t w e n t y - f o u r s u b j e c t s t e s t e d by A n d e r s o n e t a l ( 1 9 8 2 ) , b r e a t h i n g warm-humid a i r w i t h no RHL d u r i n g e x e r c i s e , showed d e c r e a s e s i n peak f l o w of g r e a t e r t h a n 10%. Anderson' has s i n c e t h e n shown t h a t w a t e r l o s s f r o m t h e mucosa i s t h e m a j o r d e t e r m i n e n t o f EIA r a t h e r t h a n RHL ( A n d e r s o n e t a l , 1982; B a r -Y i s h a y e t a l , 1 9 8 4 ) . A f l u i d l a y e r l i n e s t h e a i r w a y s w h i c h i s s l i g h t l y h y p e r o s m o l a r i n r e l a t i o n t o p l a s m a a t r e s t . As c o o l d r y a i r e n t e r s t h e a i r w a y s , w a t e r and h e a t a r e t r a n s f e r r e d f r o m t h e s u r f a c e of t h e a i r w a y s t o b r i n g t h e i n s p i r e d a i r t o body c o n d i t i o n s ( D e a l e t a l , 1979c; S t r a u s s e t a l , 1978; B a r - Y i s h a y e t a l , 1984; E g g l e s t o n , 1 9 8 6 ) . T h i s i n t u r n , c a u s e s an i n c r e a s e i n o s m o l a l i t y . The d e g r e e o f i n c r e a s e i s n o t known, h o w e v e r , h i g h l e v e l s may a c t d i r e c t l y on t h e a i r w a y s u r f a c e c e l l s ( e p i t h e l i a l c e l l s , m a c r o p h a g e s , mast c e l l s , and i r r i t a n t r e c e p t o r s : E g g l e s t o n , 1 9 8 6 ) . Once t h e p h y s i o l o g i c a l s t r e s s has been i n t r o d u c e d , a t r a n s l a t i o n a l s t e p o c c u r s w h i c h r e s u l t s i n smooth m u s c l e c o n s t r i c t i o n , o f t h e a i r w a y s ( E g g l e s t o n , 1 9 8 6 ) . The pathway o f t h i s i n t e r v e n i n g s t e p i s c u r r e n t l y n o t known. The f i r s t o f two h y p o t h e s i s i s a v a g a l r e f l e x b r o n c h o c o n s t r i c t i o n i n w h i c h i r r i t a n t r e c e p t o r s a r e d i r e c t l y s t i m u l a t e d i n t h e o r o p h a r y n x o r b r o n c h i , and l e a d t o a i r w a y c o n s t r i c t i o n ( S o u h r a d a e t a l , 1 9 8 1 ) . T h i s h y p o t h e s i s i s n o t w i d e l y a c c e p t e d b e c a u s e c h o l i n e r g i c b l o c k a d e has l i t t l e e f f e c t on EIA ( E g g l e s t o n , 1986; G o d f r e y , 1 9 7 5 ) . The s e c o n d h y p o t h e s i s i n v o l v e s t h e s t i m u l u s a c t i n g d i r e c t l y on t h e mast c e l l s c a u s i n g a l i b e r a t i o n o f b r o n c h o c o n s t r i c t o r m e d i a t o r s s u c h as h i s t a m i n e , s l o w r e a c t i n g s u b s t a n c e - a n a p h y l a x i s ( S R S - A ) , and e o s i n o p h i l c h e m o t a c t i c f a c t o r 45 (ECF-A: D e a l e t a l , 1979a; Amos, 1980; E g g l e s t o n , 1986; B a r -Y i s h a y e t a l , 1984; G o d f r e y , 1 978). In a d d i t i o n , m e d i a t o r r e l e a s e may be t r i g g e r e d by an i n c r e a s e i n o s m o l a l i t y c a u s e d by water l o s s ( E g g l e s t o n , 1986). Most of t h e e v i d e n c e s u p p o r t i n g t h i s t h e o r y i s based on t h e i n h i b i t i o n of EIA by t h e a d m i n i s t r a t i o n of d r u g s such as sodium c r o m o l y n (DSCG), 2 a d r e n e r g i c a g o n i s t s , c a l c i u m a n t a g o n i s t s , and d i e t h y l c a r b a m a z i n e which i n h i b i t s t h e r e l e a s e of SRS-A, and t h e r e f o r e p r e v e n t i n g p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n ( L e e e t a l , 1 9 84). REFRACTORY PERIOD: S e v e r a l i n v e s t i g a t o r s have d e m o n s t r a t e d t h a t two or more c o n s e c u t i v e e x e r c i s e c h a l l e n g e s , p e r f o r m e d w i t h i n two h o u r s of e a c h o t h e r r e s u l t s i n the s e c o n d c h a l l e n g e b e i n g a t t e n u a t e d by t h e f i r s t ( B a r - Y i s h a y e t a l , 1984; Edmunds e t a l , 1978; S t r a u s s et a l , 1978; G o d f r e y , 1977). The g r e a t e r i n t e n s i t y o f the i n i t i a l c h a l l e n g e , the g r e a t e r t h e d e c r e a s e i n p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n on the s e c o n d c h a l l e n g e a t t h e same i n t e n s i t y . However, i f t h e f i r s t c h a l l e n g e i s a t a l o w e r i n t e n s i t y t h an th e s e c o n d , p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i s s i m i l a r f o r t h e two t e s t s (Edmunds e t a l , 1978; E g g l e s t o n , 1 9 86). T h r e e mechanisms have been p o s t u l a t e d f o r t h i s phenomena: a d e s e n s i t i z a t i o n of t h e a i r w a y smooth m u s c l e to mast c e l l m e d i a t o r s ; d e p l e t i o n of mast c e l l m e d i a t o r s ; and i n h i b i t i o n due t o e l e v a t e d e p i n e p h r i n e l e v e l s ( S i l b e r e t a l , 1985; E g g l e s t o n , 1 9 8 6). The most a c c e p t e d h y p o t h e s i s i s t h a t t h e s t o r e d m e d i a t o r s 46 have become d e p l e t e d and r e q u i r e t i m e f o r r e s y n t h e s i s (Edmunds e t a l , 1978; James e t a l , 1976; G o d f r e y , 1977). T h i s phenomenum has s u p p o r t e d the t h e o r y t h a t warm-up p r i o r t o e x e r c i s e , i n the e x e r c i s e - i n d u c e d a s t h m a t i c , may g r a d u a l l y d i s c h a r g e t h e b r o n c h i a l c o n s t r i c t i n g m e d i a t o r s , and t h u s d e c r e a s e a i r w a y c o n s t r i c t i o n . FACTORS AFFECTING THE MAGNITUDE OF RESPONSE: The s e v e r i t y o f e x e r c i s e - i n d u c e d b r o n c h o c o n s t r i c t i o n can be e l i m i n a t e d or r e d u c e d by s e v e r a l f a c t o r s s u c h as t y p e , i n t e n s i t y , and d u r a t i o n of e x e r c i s e , l e v e l of a e r o b i c f i t n e s s , e n v i r o m e n t a l c o n d i t i o n s , p r e - e x e r c i s e m e d i c a t i o n , and warm-up e x e r c i s e . A. Type of E x e r c i s e : T h r o u g h o u t the y e a r s , many d i f f e r e n t f orms of e x e r c i s e have been used i n the i n v e s t i g a t i o n of p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i n e x e r c i s e - i n d u c e d a s t h m a t i c s ( J o n e s e t a l , 1963; F i t c h ' a n d M o r t o n , 1971; K a t z e t a l , 1971; S i l v e r m a n and A n d e r s o n , 1972; S l y , 1971; F i t c h and G o d f r e y , 1976). S e v e r a l s t u d i e s have shown f r e e r u n n i n g t o be more a s t h m o g e n i c t h a n t r e a d m i l l r u n n i n g , f o l l o w e d by c y c l i n g , d o w n h i l l r u n n i n g , swimming, w a l k i n g , and k a y a k i n g ( F i t c h , 1976; A n d e r s o n e t a l , 1975; G o d f r e y , 1975). F i t c h and M o r t o n (1971) compared swimming w i t h r u n n i n g and c y c l i n g a t a c o n t r o l l e d work i n t e n s i t y and d u r a t i o n . They r e p o r t e d t h a t swimming, compared w i t h r u n n i n g and c y c l i n g , e l i m i n a t e d or c a u s e d v e r y l i t t l e b r o n c h o c o n s t r i c t i o n , w h ich was m i l d and r e l a t i v e l y s h o r t i n d u r a t i o n . M o r t o n (1981) hi and A n d e r s o n (1972) e x p l a i n t h a t t h i s low i n c i d e n c e of asthma may be a t t r i b u t e d to the warm-humid a i r near t h e s u r f a c e of the w a t e r , p r e v e n t i n g a c o o l i n g and d e h y d r a t i o n of t h e a i r w a y s . F i t c h and G o d f r e y (197 6) p e r f o r m e d numerous s t u d i e s i n e v a l u a t i n g t h e t y p e of e x e r c i s e w i t h t h e i n c i d e n c e of p o s t -e x e r c i s e b r o n c h o c o n s t r i c t i o n . The f o l l o w i n g was r e p o r t e d : a v e r a g e d e c r e a s e of 47% i n pulmonary f u n c t i o n o c c u r e d i n f r e e -r a n g e r u n n i n g , 33% d e c r e a s e f o r t r e a d m i l l r u n n i n g , and 25% d e c r e a s e f o r c y c l i n g . T h e s e f i n d i n g s a r e s u p p o r t e d by many o t h e r s t u d i e s ( F i t c h and M o r t o n , 1971; A n d e r s o n , 1972). B. I n t e r m i t t e n t E x e r c i s e : In a d d i t i o n , i n t e r m i t t e n t , p r o g r e s s i v e or a l t e r n a t i n g ( s t e p p i n g ) forms of e x e r c i s e w i l l not p r o v o k e p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n , r e g a r d l e s s of u s i n g arms, l e g s , or b o t h ( F i t c h and G o d f r e y , 1976; M a r l e y , 1977; M o r t o n , 1981). M o r t o n (1981) has i n v e s t i g a t e d f o u r e x e r c i s e r e g i m e s : 10 s e c o n d i n t e r v a l s o f r u n n i n g w i t h 30 s e c o n d s of r e s t between r u n s ; 20 s e c o n d r u n n i n g i n t e r v a l s w i t h 60 s e c o n d s r e s t between r u n s ; 2 x 3 m inute r u n s w i t h 5 m i n u t e s r e s t between r u n s ; and 1 c o n t i n u o u s r u n of 6 m i n u t e s . The i n t e r v a l s e s s i o n s were s i g n i f i c a n t l y l e s s a s t h m o g e n i c than the c o n t i n u o u s r u n . The 10 and 20 s e c o n d r u n s were p e r f o r m e d a t a t r e a d m i l l speed t h a t was 1.75 t i m e s g r e a t e r t h a n t h e c o n t i n u o u s t r e a d m i l l speed w h i c h was h e l d between 75-85% of the i n d i v i d u a l s maximal oxygen u p t a k e . In a d d i t i o n , M o r t o n (1981) r e p o r t e d an e l i m i n a t i o n of the d i f f e r e n c e between i n t e r m i t t e n t and c o n t i n u o u s work when mi n u t e v e n t i l a t i o n r a t e s 48 were h e l d c o n s t a n t . T hese f i n d i n g s h e l p e x p l a i n why many i n d i v i d u a l s p a r t i c i p a t e i n s p o r t s t h a t a r e e p i s o d i c . C. I n t e n s i t y and D u r a t i o n of E x e r c i s e : In an e x e r c i s e - i n d u c e d a s t h m a t i c , m o d e r a t e l y h a r d e x e r c i s e a t a f i x e d t r e a d m i l l speed and g r a d i e n t c a u s e m i n i m a l e f f e c t i n pulmonary f u n c t i o n d u r i n g the f i r s t m i n ute ( A n d e r s o n , 1972; M o r t o n , 1981). B r o n c h i a l a i r w a y s p r o g r e s s i v e l y c o n s t r i c t w i t h i n c r e a s e i n work time up t o 8 m i n u t e s d u r a t i o n , however, beyond t h i s p o i n t t h e s e v e r i t y may b e g i n to d e c r e a s e ( S i l v e r m a n and A n d e r s o n , 1972; F i t c h and G o d f r e y , 1976; M o r t o n , 1981; A n d e r s o n , 1 9 7 2 ) . T h i s l a t e r phenonomen i s c o n s i s t e n t w i t h o b s e r v a t i o n a l r e p o r t s made on ' r u n n i n g t h r o u g h ' t h e asthma ( G o d f r e y , 1977; M o r t o n , 1981; F i t c h and G o d f r e y , 1976; A n d e r s o n , 1972). The s e v e r i t y of p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i s d i r e c t l y r e l a t e d t o t h e i n t e n s i t y of t h e work l o a d . A i r w a y c o n s t r i c t i o n ' i n c r e a s e s v/ith an i n c r e a s e i n t h e t r e a d m i l l s l o p e , a t a c o n s t a n t speed ( A n d e r s o n , 1972; S i l v e r m a n , 1972; M o r t o n , 1981; F i t c h , 1976). I n t e n s i t i e s of the work a p p e a r s t o have a maximum l e v e l e q u i v a l e n t to 65-75% of maximal oxygen c o n s u m p t i o n . At i n t e n s i t i e s g r e a t e r t h a n 85% maximal a e r o b i c power r e s u l t s i n l i t t l e o r no change i n t h e d e g r e e of b r o n c h o c o n s t r i c t i o n o c c u r s ( F i t c h and G o d f r e y , 1976; M o r t o n , 1981). D. A e r o b i c F i t n e s s : R e g u l a r m a i n t e n a n c e of p h y s i c a l f i t n e s s i s as i m p o r t a n t i n a s t h m a t i c s as n o n - a s t h m a t i c s (Fox and Mathews, 1981; Astrand., and R o d a h l , 1977; S l y , 1 9 76). In a d d i t i o n t o body c o m p o s i t i o n , b i o c h e m i c a l and c o n n e c t i v e t i s s u e c h a n g e s , a e r o b i c c o n d i t i o n i n g w i l l i mprove c a r d i o r e s p i r a t o r y f u n c t i o n . More s p e c i f i c a l l y , i n c r e a s e s i n pulmonary v e n t i l a t i o n , v e n t i l a t o r y e f f i c i e n c y , l u n g volumes and d i f f u s i o n c a p a c i t y o c c u r (Fox and Mathews, 1981; A s t r a n d , 1977; B r o o k s , 1984). These changes w i l l i n c r e a s e t h e t o l e r a n c e and t h r e s h o l d l e v e l s i n t h e a s t h m a t i c , r e s u l t i n g i n a h i g h e r l e v e l of p r o v o c a t i o n r e q u i r e d f o r a i r w a y c o n s t r i c t i o n ( F i t c h , 1976; S l y , 1972; M o r t o n , 1981). Many a n e c d o t a l , r e p o r t s r e v e a l a r e d u c t i o n i n m e d i c a t i o n r e q u i r e m e n t s , d e c r e a s e d f r e q u e n c y of a t t a c k s , i m p r o v e d a b i l i t y t o cope w i t h an a t t a c k and d e c r e a s e d s c h o o l a b s e n t e e i s m i n i n d i v i d u a l s c t h a t have improved t h e i r a e r o b i c f i t n e s s l e v e l ( F i t c h and G o d f r e y , 1976; M o r t o n , 1981). F i t c h ( 1 9 8 6 ) , i n a s t u d y of 26 a s t h m a t i c y o u t h s , found t h a t a r u n n i n g t r a i n i n g program had no s i g n i f i c a n t e f f e c t upon the s e v e r i t y of p o s t -e x e r c i s e b r o n c h o c o n s t r i c t i o n , however, i n d i v i d u a l s r e p o r t e d d e c r e a s e s i n the f r e q u e n c y and d u r a t i o n of a t t a c k s i n e v e r y d a y l i f e . E. E n v i r o n m e n t a l C o n d i t i o n s : P r e v i o u s d i s c u s s i o n d i s c l o s e d t h a t t h e p h y s i o l o g i c a l s t r e s s i n i t i a t i n g p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i s t h e c o o l i n g and d e h y d r a t i o n of t h e a i r w a y s ( D e a l e t a l , 1979a; S t r a u s s e t a l , 1 9 7 8 ) . I n h a l i n g c o o l d r y a i r i n c r e a s e s t h e d e g r e e of a i r w a y c o n s t r i c t i o n , w h i l e a warm-humid e n v i r o n m e n t c a u s e s l e s s 50; c o n s t r i c t i o n i n most e x e r c i s e - i n d u c e d a s t h m a t i c s . F. P r e - e x e r c i s e m e d i c a t i o n : P h a r m a c e u t i c a l management, p r i o r t o e x e r c i s e , has a l l o w e d i n d i v i d u a l s w i t h e x e r c i s e - i n d u c e d a s t hma t o p a r t i c i p a t e i n p h y s i c a l a c t i v i t y w i t h o u t t h e o n s e t o f b r o n c h o c o n s t r i c t i o n . The a d m i n i s t r a t i o n o f s y m p a t h e m i m e t i c d r u g s , t h e o p h y l l i n e , c r o m o l y n s o d i u m ( d i s o d i u m c r o m o g l y c a t e ) , o r d i e t h y l c a r b a m a z i n e p r i o r t o e x e r c i s e has been w i d e l y u s e d ( A n d e r s o n , 1972; S l y , 1976; G o d f r e y , 1970; F i t c h , 1 9 8 6 ) . U n f o r t u n a t e l y , t h e I n t e r n a t i o n a l O l y m p i c C o m m i t t e e ( I O C ) and U n i t e d S t a e s O l y m p i c C o m m i t t e e (USOC) have banned t h e use o f n o r e p i n e p h r i n e , e p h e d r i n e , and o t h e r - a d r e n e r g i c d r u g s t h a t have been h i g h l y e f f e c t i v e i n r e d u c i n g o r e l i m a t i n g E I A . 2 a d r e n e r g i c d r u g s s u c h as a l b u t e r o l and t e r b u t a l i n e , a r e p e r m i t t e d by t h e IOC b e c a u s e t h e y r e d u c e e x e r c i s e - i n d u c e d b r o n c h o s p a m w i t h o u t e n h a n c i n g p e r f o r m a n c e by a d d i t i o n a l s t i m u l a t i o n ( V o y , 1986) . G. Warm-up and E I A : Warm-up has been u t i l i z e d by a t h l e t e s as a means of p r e p a r i n g t h e body p h y s i o l o g i c a l l y and p s y c h o l o g i c a l l y f o r p h y s i c a l p e r f o r m a n c e . An a c t i v e warm-up i n c r e a s e s b l o o d f l o w and ox y g e n a v a i l i b i l i t y ; m u s c l e and body c o r e t e m p e r a t u r e ; enzyme a c t i v i t y and s u b s t r a t e u t i l i z a t i o n , and t h e r e f o r e t h e r a t e of m e t a b o l i c p r o c e s s e s , p h y s i c a l work c a p a c i t y , and n e r v e c o n d u c t i o n ( A s t r a n d and R o d a h l , 1977; Fox and Mathews, 1 9 8 1 ) . I n a d d i t i o n , 51 i t d e c r e a s e s muscle c o n t r a c t i o n t h u s a i d i n g i n t h e p r e v e n t i o n of i n j u r i e s ( K l a f s and Arnheim, 1977). Warm-up i n t h e e x e r c i s e - i n d u c e d a s t h m a t i c p r i o r t o e x e r c i s e may g r a d u a l l y d i s c h a r g e the b r o n c h i a l c o n s t r i c t i n g m e d i a t o r s ( h i s t a m i n e , SRS-A, and ECF-A) from t h e mast c e l l s ( G o d f r e y , 1977), and a l t e r the i n c i d e n c e and s e v e r i t y of b r o n c h o c o n s t r i c t i o n ( M o r t o n e t a l , 1 9 81). F i t c h (1975) r e p o r t e d t h a t a warm-up i m p r o v e s t h e v e n t i l a t i o n / p e r f u s i o n r a t i o i n e x e r c i s i n g a s t h m a t i c s . As m e n t i o n e d e a r l i e r , t h e most p o p u l a r t h e o r y on t h e mechanism o f t h e r e f r a c t o r y p e r i o d h e l p s s u p p o r t G o d f r e y s ' h y p o t h e s i s of g r a d u a l m e d i a t o r d e p l e t i o n . PREVIOUS STUDIES ON WARM-UP AND EIA: Many a n e c d o t a l r e p o r t s d e m o n s t r a t e l e s s b r o n c h o c o n s t r i c t i o n f o l l o w i n g a warm-up of s t r e t c h i n g , j u m p i n g , s h o r t s p r i n t s , and g y m n a s t i c a c t i v i t i e s f o r 20 m i n u t e s p r i o r t o e x e r c i s e ( M o r t o n e t a l , 1981; ' E i s e n s t a d t , 1984; G o d f r e y , 1977; F i t c h , 1 9 7 5). However, o n l y 2 s t u d i e s have been u n d e r t a k e n to examine the e f f e c t - warm-up has on p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n i n e x e r c i s e - i n d u c e d a s t h m a t i c s . M o rton and c o l l e a g u e s (1979) t e s t e d 18 a t o p i c i n d i v i d u a l s (mean age 19.7 y e a r s ) t o d e t e r m i n e t h e e f f e c t of 'warm-up' on e x e r c i s e - i n d u c e d asthma. Each s u b j e c t p e r f o r m e d 5 m i n u t e s of submaximal t r e a d m i l l r u n n i n g to a c h i e v e a h e a r t r a t e o f 85% of p r e d i c t e d maximum f o r age. One of t h e two t e s t s , was p r e c e e d e d by a warm-up e x e r c i s e of 3 m i n u t e s of w a l k i n g a t 60% of p r e d i c t e d 52 maximal h e a r t r a t e . A l t h o u g h M o r t o n f a i l e d t o show s i g n i f i c a n c e i n p o s t - e x e r c i s e b r o n c h o c o n s t r i c t i o n between the tv/o t e s t s , he recommends t h a t a l o n g e r more i n t e n s e 'warm-up' i n v o l v i n g i n t e r v a l e x e r c i s e needs t o be e v a l u a t e d . S c h n a l l and Landau ( 1 9 8 0 ) i n v e s t i g a t e d f o u r males and two f e m a l e s ( a g e s 12 to 31 y e a r s ) under t h r e e e x p e r i m e n t a l c o n d i t i o n s : A; 2 x 6 m i n u t e r u n s w i t h a 4 9 m i n u t e r e s t between r u n s ; B: 6 minute r u n , f o l l o w e d by 10 m i n u t e s o f r e s t and 7 x 3 0 s e c o n d s p r i n t s ( 2 . 5 m i n u t e s r e s t between s p r i n t s ) ; and C: 7 x 3 0 s e c o n d s p r i n t s ( 2 . 5 m i n u t e s r e s t between s p r i n t s ) f o l l o w e d by 20 m i n u t e s o f r e s t and a 6 m i n u t e r u n . I t was f o u n d t h a t t h e s h o r t s p r i n t s d i d not i n d u c e b r o n c h o c o n s t r i c t i o n , but r e s u l t e d i n l e s s b r o n c h o c o n s t r i c t i o n a f t e r a 6 minute r u n . T h i s s t u d y was d e s c r i p t i v e , and the a u t h o r s recommended t h a t a more homogeneous group undergo e x a m i n a t i o n , w i t h s t a t i s t i c a l a n a l y s i s . 53 APPENDIX B. INDIVIDUAL PHYSIOLOGICAL DATA S u b j e c t Age ( y r s ) Sex H e i g h t (cm) Weight (kg) V02max (ml/kg/min PC20 ) (mg/ml) 1 24 F 159.8 53.0 54.4 0.50 2 22 F 170.0 68.0 50.3 0.26 3 24 M 181.2 65.8 52.5 0.70 4 25 F 158.0 55.5 50.1 0.50 5 21 F 160.8 50.7 56.1 0.26 6 20 M 187 .0 79.6 59.0 0.20 7 42 M 165 . 5 75.3 45.6 0.26 8 42 F 170.6 62.5 56.7 0.10 9 25 F 159.7 57.5 59.2 0.50 10 23 F 165.5 56.6 51.6 4.00 11 23 F 165".5 56.6 51.6 0.70 12 28 F 171.5 66.3 45.0 4.00 MEAN 26 .5 169.2 64.3 52.5 1 .00 • SD 7.8 9.5 10.3 4.7 1.4 54 APPENDIX C. INDIVIDUAL PULMONARY FUNCTION DATA (1 i t e r s ) P r e d i c t e d I n i t i a l H i s t a m i n e V e n t o l i n S u b j e c t FEVl.O/FVC FEVl.O/FVC F E V l .0 F E V l . 0 1 3.07/3.77 2.98/3.37 2.00 2.57 2 3.47/4.27 3.24/4.20 2.50 3.27 3 4.42/5.54 4.12/5.53 2.61 3.96 4 2.97/3.66 2.59/3.19 2.05 2.82 5 3.04/3.70 2.86/3.46 2.56 3.01 6 4.79/6.01 4.60/7.03 2.56 4.43 7 2.10/2.88 2.00/2.84 1.46 2.04 8 2.97/3.79 2.00/3.88 0.94 2.58 9 3.29/4.02 3.90/4.15 2.98 4.05 10 3.27/4.02 3.20/3.77 3.08 3.39 11 3.60/4.45 3.48/4.40 2.98 3.48 12 • 3.39/4.42 3.73/4.05 3.28 3.62 55 APPENDIX D. INDIVIDUAL PULMONARY FUNCTION DATA: % CHANGE UNDER EACH CONDITION Subject NW CW IW %FEV 1 . 0 1 3 9 . 0 1 2 . 0 3 4 . 0 2 5 1 . 0 3 0 . 0 4 5 . 0 3 2 0 . 0 7 . 8 1 7 . 0 4 3 7 . 0 2 1 . 0 2 8 . 0 5 3 2 . 0 1 8 . 0 2 4 . 0 6 3 7 . 7 2 1 . 5 3 0 . 9 7 3 0 . 0 2 0 . 0 3 0 . 0 8 7 6 . 6 4 2 . 0 6 1 . 0 9 2 5 . 6 1 0 . 3 2 8 . 7 1 0 1 6 . 9 2 . 7 1 6 . 6 11 2 7 . 7 9 . 7 2 7 . 7 12 2 1 . 7 5 . 2 1 3 . 8 3 4 . 6 ± 1 6 . 3 1 6 . 7 t H . 2 2 9 . 7 i 1 3 . 0 %MMEFR 1 4 9 . 0 1 8 . 0 4 9 . 0 2 6 4 . 0 4 7 . 0 5 9 . 0 3 3 5 . 0 1 8 . 0 3 5 . 0 4 6 6 . 0 4 9 . 0 6 4 . 0 5 6 9 . 0 4 2 . 0 5 1 . 0 6 6 0 . 3 3 6 . 8 5 2 . 7 7 5 4 . 0 4 2 . 0 5 5 . 0 8 8 1 . 0 5 7 . 0 7 0 . 0 9 3 6 . 0 1 3 . 3 2 8 . 0 1 0 1 1 . 4 5 . 4 7 . 6 11 4 0 . 7 2 8 . 1 4 2 . 0 12 3 1 . 0 6 . 5 7 . 9 5 0 . 0 + 1 9 . 5 3 0 . 2 ± 1 7 . 7 4 3 . 4 ± 2 0 . 3 %FVC 1 3 0 . 0 5 . 0 1 4 . 0 2 4 3 . 0 2 5 . 0 4 0 . 0 3 3 . 6 5 . 5 5 . 5 4 1 7 . 0 8 . 0 1 4 . 0 5 1 5 . 0 8 . 0 1 0 . 0 6 1 7 . 5 1 1 . 5 1 4 . 1 7 2 0 . 0 3 . 0 1 9 . 0 8 6 6 . 0 2 4 . 0 4 7 . 0 9 2 5 . 0 1 5 . 2 3 2 . 9 1 0 1 4 . 6 9 . 5 1 8 . 7 11 1 8 . 6 0 . 0 2 0 . 0 12 1 7 . 4 8 . 6 1 7 . 2 3 0 . 0 + 1 2 . 3 1 0 . 7 ± 7 . 7 2 1 . 0 + 1 2 . 5 56 APPENDIX E . INDIVIDUAL FEV1.0 AND % CHANGE IN FEV1.0 FOR EACH CONDITION Subject Control FEV1.0 %A Cont Warm-up FEV1.0 %A Int . Warm-up FEV1.0 % A 4: 6: 7: 8: 10 11 Base: 1.85 2.00 1.92 Post Rx: 1.85 2.02 1 . o f 1.95 1 .Of Post Ex: 1.14 39.04; 1.75 12.01- 1.26 34.04 Base: 3.40 3.10 3.05 . Post Rx: 3.40 2.72 12.04 3.40 11.0* Post Ex: 1.65 51.01- 2.17 30.01 1.68 * 45.04 Base: 4.45 4.50 4.45 Post Rx: 4.45 4.30 4.04, 4.40 1.0* Post Ex: 3.56 20.04- 4.15 7.81- 3.70 17.04 Base: 2.60 2.48 „ _ 2.60 _ — — _ Post Rx: 2.60 2.35 5.01 2.72 5.0* Post Ex: 1.64 37.04- 1.95 21. 04 1.86 28.04-Base: 2.86 2.85 2.90 Post Rx: 2.86 2.80 2.04 2.80 3.04 Post Ex: 1.95 32.04- 2.33 18.04 2.20 24.04 Base : 5.30 _ . — _ _ 4.52 4.70 . Post Rx: 5.30 4.00 11.54 4.20 10.64 Post Ex: 3.30 37.71 3.55 21.54 3.25 30.94 Base: 1.90 1.75 2.15 Post Rx: 1.90 — • 1.40 19.04 2.40 12. Of Post Ex: 1.34 30.01 1.40 20.0* 1.50 30.04 Base : 2.74 3.10 2.60 Post Rx: 2.74 3.00 3.04 2.50 4.04 Post Ex: .64 76.61- 1.80 42.04 1.01 61.04 Base: 3.90 3.90 3.90 Post Rx: 3.90 4.00 2.6t 3.94 1 .0T Post Ex: 2.90 25.61 3.50 10.3 i 2.78 28.74 Base : 3.85 3.70 3.84 Post Rx: 3.85 3.70 3.80 1.04 Post Ex: 3.20 16.9i 3.60 2.74 3.20 1 6 . 6 ± Base: 4.15 3.90 3.90 • _ • Post Rx: 4.15 4.03 3.0 t 3.74 4.04 Post Ex: 3.00 27.7 J, 3.52 9.7 j, 2.82 1 3 .84 Base : 4.15*' 3.85 4.20 Post Rx: 4.15 4.05 5.2T 4.10 2.44-Post Ex: 3.25 21 .71 3.65 5.24 3.62 13.84, 57 APPENDIX F. INDIVIDUAL MMEFR AND % CHANGE IN MMEFR FOR EACH CONDITION C o n t r o l Cont Warm-up I n t . Warm-up S u b j e c t MMEFR % A MMEFR % A MMEFR % A 1 : Base P o s t P o s t Rx: Ex: . 7 7 . 7 7 . A O 4 9 . 0 1 1 . 0 7 1 . 2 0 . 8 8 1 2 . Ot 1 8 . 0 1 . 9 8 1 . 2 0 . 5 0 2 2 . Ot A 9 . 0 L 2 : Base P o s t P o s t Rx: Ex: 2 . 4 4 2 . A A . 8 7 6 4 . 0 1 2 . A 3 1 . 5 8 1 . 0 A 3 5 . 0 1 4 7 . 0 1 2 . 1 8 2 . 5 9 . 8 9 1 9 . 0 T 5 9 . 0 J , 3 : Base P o s t P o s t Rx: Ex: A . 0 3 A . 0 3 2 . 5 0 3 8 . 0 1 A . 3 8 3 . 6 1 3 . 5 7 1 8 . 0 1 1 8 . 0 1 4 . 0 3 A . 0 3 2 . 6 0 3 5 . 0 1 A : Base P o s t P o s t Rx: Ex: 2 . 5 0 2 . 5 0 . 8 6 6 6 . 0 1 2 . 0 1 1 . 6 3 1 . 0 2 19.0V 4 9 . 0 1 2 . 7 6 2 . 5 8 1 . 0 0 6 . 5 1 6 A . 0 1 5 : Base P o s t P o s t Rx: Ex: 3 . 8 0 3 . 8 0 1 . 1 8 6 9 . CU 3 . 0 5 3 . 3 3 1 . 7 5 9 . 0 * 4 2 . 0 1 3 . 2 6 3 . A 8 1 . 5 9 6 . 7 t 5 1 . 0 1 6 : Base P o s t P o s t Rx: Ex : A . 1 3 A . 1 3 1 . 6 4 6 0 . 31 2 . 8 8 3 . 6 8 1 . 8 2 2 7 . 8 t 3 6 . 8 1 3 . 2 7 2 . 3 8 1 . 7 2 2 7 . 1 1 5 2 . 7 1 7 : Base P o s t P o s t Rx: Ex: 1 . 3 0 1 . 3 0 . 6 0 5 4 . 0 1 1 . 4 0 1 . 3 3 . 8 1 5 . 0 1 4 2 . 0 1 1 . 7 1 1 . A 5 . 7 7 1 5 . 0 1 5 5 . 0 1 8 : Base P o s t P o s t Rx: Ex: 1 . 7 8 1 . 7 8 . 3 4 8 1 . 0 1 2 . 0 7 1 . 6 9 . 8 8 18.04. 5 7 . 0 1 1 . 8 3 1 . 5 2 . 5 4 1 7 . 0 1 7 0 . 0 1 9 : Base P o s t P o s t Rx: Ex: 5 . 1 5 5 . 1 5 3 . 2 8 3 6 . 0 ^ 5 . 0 5 5 . 1 5 4 . 3 8 2 . 0 T 1 3 . 3 1 4 . 8 8 5 . 2 6 3 . 5 1 ' 7 . 7 * 2 8 . 0 1 1 0 : Base P o s t P o s t Rx: Ex : 4 . 7 2 4 . 7 2 4 . 1 8 11 . A l A . 6 5 4 . 4 2 A . A 2 5 . 0 1 5 . 4 1 A . 6 3 5 . 6 0 A . 2 8 2 1 . 0 * 7 . 6 1 11 : Base P o s t P o s t Rx : Ex: 3 . 8 1 3 . 8 1 2 . 2 6 A O . 7 1 3 . 5 6 3 . 3 2 2 . 5 6 6.61 2 8 . 1 1 3 . 2 1 3 . 0 1 1 . 8 7 6 . 0 1 4 2 . 0 1 1 2 . Base P o s t P o s t Rx: Ex: 4 . 1 8 4 . 1 8 2 . 8 9 3 1 . 0 L 3 . 8 3 4 . 7 5 3 . 5 8 2 4 . 0 * 6 . 5 1 A . 5 6 A . 6 0 A . 2 0 , 9 t 7 . 9 1 58 APPENDIX G. INDIVIDUAL FVC AND % CHANGE IN FVC FOR EACH CONDITION C o n t r o l Cont Warm-up I n t . Warm-up S u b j e c t FVC % A FVC % A FVC % A 1 : Base : P o s t Rx: P o s t Ex: 3 . 3 2 3 . 3 2 2 . 3 2 3 0 . 0 1 3 . 4 2 3 . 4 0 3 . 2 5 0 .01-5 . 0 4 3 . 2 5 3 . 1 0 2 . 8 0 5 . 0 4 1 4 . 0 4 2 : Base : P o s t Rx: P o s t Ex: 4 . 4 0 4 . 4 0 2 . 5 0 4 3 . 0 J 4 . 1 5 3 . 9 5 3 . 1 0 5 . 0 4 2 5 . 0 4 4 . 1 5 4 . 4 5 2 . 5 0 7.0t 4 0 . 0 4 3 : Base : P o s t Rx: P o s t Ex: 5 . 2 4 5 . 2 4 5 . 0 5 3 . 6 1 5 . 2 4 5 . 1 5 4 . 9 5 1 .71 5 . 5 4 5 . 2 4 5 . 2 0 4 . 9 5 7 . 6 4 5 . 5 4 4 : Base : P o s t Rx: P o s t Ex: 3 . 0 0 3 . 0 0 2 . 4 8 1 7 . 0 1 3 . 1 0 2 . 9 5 2 . 8 5 5 . 0 4 8 . 0 4 ' 3 . 2 5 • 3 . 1 0 2 . 8 0 4 . 6 4 1 4 . 0 4 5 : B a s e : P o s t Rx: P o s t Ex: 3 . 4 6 3 . 4 6 2 . 9 5 1 5 . 0 1 3 . 3 5 3 . 0 0 3 . 0 8 1 0 . 0 4 8 . 0 4 3 . 3 4 3 . 1 0 3 . 0 1 7 . 0 4 1 0 . 0 I 6 : B a s e : P o s t Rx: P o s t Ex: 6 . 8 5 6 . 8 5 5 . 6 5 1 7 . 5 4 6 . 1 0 4 . 8 5 5 . 4 0 2 0 . 5 4 1 1 . 5 4 6 . 4 0 6 . 2 0 5 . 5 0 3 . 1 4 1 4 . 1 4 7 : B a s e : P o s t Rx: P o s t Ex: 2 . 6 0 2 . 6 0 2 . 0 8 2 0 . 0 i 2 . 2 2 2 . 9 2 2 . 1 5 3 2 . 0 ^ 3.04 2 . 8 4 3 . 2 2 2 . 3 0 1 3 . 0 4 1 9 . 0 4, 8 : Base : P o s t Rx: P o s t Ex : 3 . 9 2 3 . 9 2 1 . 3 2 66.0], 4 . 1 9 4 . 3 4 3 . 2 0 4 . O f 2 4 . 0 V 3 . 7 8 3 . 6 6 2 . 0 0 3 . 0 4 4 7 . 0 4 9 : B a s e : P o s t Rx: P o s t Ex: 4 . 1 2 4 . 1 2 3 . 1 0 2 5 . 0 1 4 . 1 5 4 . 1 0 3 . 4 2 1 . 2 4 1 5 . 2 4 4 . 2 0 4 . 0 3 2 . 8 2 2 . 9 4 3 2 . 9 4 1 0 : B a s e : P o s t Rx: P o s t Ex: 3 . 9 8 3 . 9 8 3 . 4 0 1 4 . 6 4 4 . 0 0 3 . 9 7 3 . 6 2 0 . 8 4 9 . 5 4 4 . 0 0 3 . 9 2 3 . 2 5 6 . 2 1 1 8 . 7 4 11 : Base : P o s t R x: P o s t Ex: 5 . 1 0 - 5 . 1 0 4 . 1 5 1 8 . 6 1 4 . 6 4 5 . 1 2 4 . 6 2 1 0 . 0 * 4 . 9 5 4 . 8 2 3 . 9 8 3 . 0 4 2 0 . 0 4 12 . B a s e : P o s t Rx: P o s t Ex: 4 . 6 0 4 . 6 0 3 . 3 0 1 7 . 4 ^ 4 . 6 0 4 . 3 8 4 . 2 0 4 . 8 4 8 . 6 4 4 . 6 5 4 . 3 2 3 . 8 5 7 . 1 9 4 1 7 . 2 1 59 APPENDIX H RESPIRATORY HEAT LOSS ( S t r a u s s et a l , 1977) RHL = VE (HC ( T i - T e ) + HV (WCi-WCe)) RHL = R e s p i r a t o r y Heat Loss (kcal/min) VE = V e n t i l a t i o n (1/min; BTPS) HC = Heat C a p a c i t y of A i r = s p e c i f i c heat x d e n s i t y = 0.000304 k c a l / 1 per °C T i = I n s p i r e d a i r temperature ("C) Te = E x p i r e d a i r temperature (°C) HV = Heat of V a p o r i z a t i o n of Water = 0.58 k c a l / g = .00058 kcal/mg WCi = Water content of i n s p i r e d a i r (mg water/1 a i r ) WCe = Water content of e x p i r e d a i r (mg water/1 a i r ) Example: Subject No.l ( C o n t r o l ) RHL = 84.5 (.000304 (21.0-31.9) + .00058 (11.5-32.8)) = 84.5 (.000304 (-10.9) + .00058 (-21.3)) = 8.4.5 (-.0033 + -.0124) = 84.5 (-.0157) = -1.32 kcal/min 6 0 APPENDIX I . INDIVIDUAL RESPIRATORY HEAT LOSS DATA at 1, 3 AND 5 MINUTES (H = 7) Subject T i RH WC i 1 Te 3 5 1 WCe 3 5 C o n t r o l : 1 21. 0 63 .0 11. 5 31 .2 31. .6 31 .2 32 .5 33 .2 32. .8 2 22. 0 68 .0 13. 1 32 .2 32, .6 32 .7 34 .2 34 .9 35. .1 3 19. 5 54 .0 8. 3 31 .3 31. ,8 32 .1 32 .8 33 .5 34. .0 4 20. 5 62 .0 12. 3 31 .8 32, .1 32 .1 33 .5 34 .0 34. .0 5 18. 8 56 .0 9. 0 30 .9 31. .5 31 .6 31 .9 33 .0 33. .2 6 21. 5 61 .0 11. 5 32 .5 32. .5 32 .6 34 .7 34 .7 34, .9 7 21. 5 72 .0 13. 5 31 .5 31. .8 32 .0 33 .0 33 .5 33. .8 Continuous Warm- up Condit ion ' 1 18. 5 70 .0 11. 1 31 .7 32. .1 32 .3 33 .4 34 .0 34, .4 2 22. 5 54 .0 10. 7 32 .8 32, .9 33 .0 34 .1 35 .5 35, .7 3 19. 5 50 .0 8. 5 31 .8 32. .3 32 .4 33 .5 34 .3 34, .5 4 19. 5 64 .0 10. 8 30 .9 31, .6 31 .8 31 .9 33 .2 33, .5 5 18. 0 56 .0 8. 6 31 .2 31, .6 31 .7 32 .5 33 .2 33, .3 6 20. 0 70 .0 12. 1 32 .5 32, .8 32 .9 34 .7 35 .1 35, .5 7 22. 5 54 .0 10. 7 32 .1 32, .5 32 .7 34 .0 34 .7 35, .1 Interval . Wa rm--up Condi t ion: 1 20. 5 66 .0 11. 7 31 .7 32, .2 32 .6 33 .3 34 .2 34. .5 2 23. 0 78 .0 15. 8 33 .2 33, .6 33 .7 36 .1 36 .8 37, .1 3 18. 5 52 .0 8. 3 31 .4 32, .3 32 .3 32 .8 34 .3 34. .3 4 19. 5 62 .0 10. 4 31 .6 31, .8 32 .1 32 .5 33 .5 34, .0 5 20. 0 57 .0 9. 9 32 .2 32, .4 32 .5 34 .2 34 .5 34. .7 6 21. 0 72 .0 13. 1 33 .0 33, .4 33 .7 35 .7 36 .4 37. .1 7 22. 5 68 .0 13. 5 31 .6 32, .2 32 .4 33 .2 34 .2 34. .5 T i = i n s p i r e d a i r temperature ( ° C ) RH = r e l a t i v e humidity (%) WCi = water content i n s p i r e d (mg water/1 a i r ) Te = expiratory a i r temperature ( ° C ) WCe = water content expired (mg water/1 a i r ) Ve = v e n t i l a t i o n ( l /min:BTPS) RHL = resp ira tory heat loss (kcal /min) 61 A P P E N D I X I ( c o n t ' d ) V e R H L M E A N R H L 1 3 5 1 3 5 5 4 . 5 7 8 . 6 8 4 . 5 0 . 8 3 1 . 2 4 1 . 3 2 1 . 1 3 8 1 . 3 8 7 . 3 8 2 . 0 1 . 2 4 1 . 3 8 1 . 3 1 1 . 3 1 4 5 . 0 7 5 . 0 8 0 . 0 0 . 8 0 1 . 3 7 1 . 5 0 1 . 2 2 6 0 . 3 5 9 . 3 6 4 . 6 0 . 9 6 1 . 0 0 1 . 0 7 1 . 0 1 4 7 . 9 5 0 . 0 6 5 . 3 0 . 8 1 0 . 8 8 1 . 1 7 0 . 9 5 1 2 0 . 0 1 2 2 . 7 1 2 2 . 7 2 . 0 2 2 . 0 6 2 . 0 8 2 . 0 5 4 4 . 0 5 4 . 0 5 1 . 3 0 . 6 3 0 . 7 9 0 . 7 7 0 . 7 3 7 1 . 3 8 0 . 0 8 4 . 0 1 . 2 0 1 . 3 9 1 . 4 8 1 . 3 5 7 0 . 0 7 3 . 3 7 8 . 3 1 . 2 2 1 . 2 9 1 . 3 8 1 . 2 9 5 4 . 0 6 5 . 0 7 6 . 7 0 . 9 8 1 . 2 2 1 . 4 6 1 . 2 2 5 1 . 0 6 0 . 0 6 5 . 0 0 . 8 1 1 . 0 0 1 . 1 1 0 . 9 7 4 4 . 0 6 0 . 0 6 0 . 0 0 . 7 9 1 . 1 1 1 . 1 2 1 . 0 1 9 4 . 6 1 2 3 . 0 1 3 2 . 7 1 . 6 0 2 . 2 1 2 . 3 1 2 . 0 3 3 4 . 0 5 0 . 0 5 2 . 7 0 . 5 6 0 . 8 5 0 . 9 1 0 . 7 7 4 8 . 7 7 5 . 4 8 1 . 3 0 . 7 8 1 . 2 4 1 . 3 7 1 . 1 3 6 5 . 0 7 6 . 7 8 2 . 6 0 . 9 7 1 . 1 8 1 . 2 9 1 . 1 9 5 3 . 3 8 0 . 0 8 2 . 7 0 . 9 6 1 . 5 4 1 . 5 9 1 . 3 6 5 2 . 7 6 3 . 0 6 8 . 7 0 . 8 6 1 . 0 9 1 . 2 0 1 . 0 5 4 8 . 0 6 2 . 0 6 1 . 3 0 . 8 5 1 . 1 2 1 . 1 2 1 . 0 3 8 6 . 0 1 0 2 . 7 1 1 4 . 0 1 . 4 4 1 . 7 7 2 . 0 3 1 . 7 5 3 8 . 0 5 2 . 7 4 8 . 0 0 . 5 4 0 . 7 9 0 . 7 3 0 . 6 9 62 APPENDIX J . EXERCISE-CHALLENGE PROTOCOL I . E x e r c i s e - c h a l l e n g e T e s t ( B a s e l i n e ) : Time (min) P r o c e d u r e s P r e S p i r o m e t e r R e a d i n g s 0:00 1:00 Gas Temp./Volume 3:00 t» EXERCISE CHALLENGE RUN ( 9 0 % V02 max) 5:00 ti 6 :00 6:30 S p i r o m e t e r R e a d i n g s 8:00 10:00 » 12:00 . 14:00 16:00 RECOVERY 18:00 20:00 22:00 26 :00 31 : 00 63 APPENDIX K. EXERCISE-CHALLENGE PROTOCOL I . E x e r c i s e - challenge Test (Continuous Warm-up): Time (min ) Procedures Pre Spirometer Readings 0:00 1:00 Gas Temp./Volume 5:00 10:00 1! I T CONTINUOUS WARM-UP (60% V02 max) 14:00 15:00 I I 16:00 Spirometer Readings 17 :00 18:00 Gas Temp./Volume 20:00 22 :00 23:00 it I I EXERCISE CHALLENGE RUN (90% V02 max) 23:30 Spirometer Readings 25:00 27 :00 29:00 31 :00 33:00 RECOVERY 35 :00 37 :00 39:00 43 :00 48:00 » APPENDIX L. EXERCISE-CHALLENGE PROTOCOL I . E x e r c i s e -c h a l l e n g e T e s t ( I n t e r v a l Warm-up): Time (min ) P r o c e d u r e s P r e S p i r o m e t e r R e a d i n g s 0:00 S p r i n t 0:30 R e s t 2:00 S p r i n t 2:30 R e s t 4:00 S p r i n t INTERVAL WARM-UP 4:30 R e s t (8 x 30 s e c . 100% V02 max) 6:00 S p r i n t 6:30 R e s t 8:00 S p r i n t 8:30 R e s t 10:00 S p r i n t 10:30 R e s t 12:00 S p r i n t 12:30 R e s t 14:00 S p r i n t 14:30 R e s t 15:30 S p i r o m e t e r R e a d i n g 16:30 17 :30 Gas Temp./Volume 19:30 " EXERCISE CHALLENGE RUN ( 9 0 % V02 max) 21 :30 22:30 23 :00 S p i r o m e t e r R e a d i n g s 24:30 26:30 28: 30 30:30 32:30 RECOVERY 34:30 36:30 38:30 42:30 47:30 " 65 

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