UBC Theses and Dissertations
Cardiorespiratory and metabolic responses to treadmill versus water immersion to the neck exercise in elite distance runners Frangolias, Despina Daisy
The purpose of this study was to compare the following: a) the cardiorespiratory responses, in elite endurance runners familiar with water immersion to the neck non—weight bearing ( WI) running, at ventilatory threshold (Tvent) and at maximal effort (ie. VO2m) for treadmill and WI running performance to exhaustion and b) the cardiorespiratory and metabolic responses to prolonged performance (42 mm.) at exercise intensities reflecting the treadmill and WI Tvent. Thirteen endurance trained runners familiar with water running completed comparable treadmill and WI VO2max tests. Oxygen consumption (V02), ventilation (ye), heart-rate (HR), respiratory exchange ratio (RER), ratings of perceived exertion ( RPE) and stride frequency (SF) were measured at Tvent and VO2max. Blood lactate [BLa] samples were obtained 30 seconds and 5 minutes post—test. Correlated t—tests revealed significantly (p<O.05) higher VO2max (59.7 vs 54.6 mlkgmin), HRmax (190 vs 175 bpm), RERmax (1.20 vs 1.10), V02 at Tvent (46.3 vs 42.8 mlkgmin1),HR at Tvent (165 vs 152 bpm) for the treadmill vs WI, respectively. Similar values were recorded for Vemax (109.0 vs 105.8 lmin), Ve at Tvent (66.4 vs 65.7 lmin), RER at Tvent (0.99 vs 0.89) and post—test [BLaJ at 30 sec (10.4 vs 9.8 mmoll) and 5 mm post—test (9.7 vs 9.2 mmoll1)for the two conditions. Wilcoxons matched pairs signed—ranks test revealed no differences in RPE at Tvent and VO2max level for the two conditions. Significantly higher SF values over time were recorded (88 vs 54 stridesmin, averaged over time) on the treadmill. The lower WI VO2max with similar peak [ BLa) and lower SF suggests that the active musculature and muscle recruitment patterns differ in WI running due to the high viscocity friction of water, and the non—weight bearing nature of WI running. During steady state exercise at treadmill and WI Tvent no differences in Ve response to exercise were noted in the treadmill and WI conditions. [BLa] response exhibited a decreasing trend over time in the WI condition both during the treadmill and WI Tvent intensity tests. Similar HR values were exhibited for exercise at WI Tvent in both conditions, confirming that the lower HR exhibited at Tvent from the WI VO2max test was related to the lower V02 at WI Tvent and not the WI condition. Significantly lower HR values were exhibited for exercise at treadmill Tvent in the WI versus the treadmill condition suggesting that HR is lower only at workloads corresponding to and above 84.8 % of WI VO2max. Results suggest that exercise in the water immersion to the neck condition affects ( reduces) HR and [BLa) response over time, with the intensity of exercise being a factor. The WI condition, however does not affect Ve and RPE responses.
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