Open Collections

The effect of active recovery on the post-exercise diffusion capacity

University of British Columbia

The purpose of this study was to investigate the effect of active recovery on the post-exercise pulmonary diffusion capacity (DL) and its two components, alveolar-capillary membrane diffusion capacity (DM) and pulmonary capillary blood volume (Vc). Ten trained non-smoking male cyclists ( age= 22 ± 2 yrs; ht = 177.4 ±7.1 cm; mass = 70.3 ± 9.1 kg; V0₂max = 61.0 ± 4.4 ml/kg/min) were recruited for this study. All subjects demonstrated normal pulmonary function with no history of respiratory disease. All spirometry and diffusion measurements were administered using the Collins PLUS DS II pulmonary function testing unit. Subjects cycled to exhaustion to determine maximal oxygen consumption (V0₂max) and ventilatory threshold (VT) on an electronically-braked cycle ergometerin their first visit. In the following two experimental trials labeled active recovery (AR) and inactive recovery (IR), all pulmonary diffusion measurements were performed. In both sessions, pre-exercise baseline values for DLco, DM and Vc were first obtained. Subjects then performed 45 minutes of cycling exercise at the individual's VT with maximal effort near the end. In only the AR trial, subjects performed an additional 30 minutes of cycling at 10% of individual's maximal power output immediately following the 45-minute exercise bout. Two additional pulmonary diffusion capacity measurements were made at 1 and 2 hours following the 45-minute submaximal exercise test. DM and Vc were calculated by measuring DLco at two inspired 0₂ concentrations using the technique of Roughton and Forster (1957). DLco was significantly reduced 1 hour post-exercise (p<0.05) and further reduced during the second hour of seated recovery in both AR and IR conditions (p<0.01). A significant reduction in DM following exercise was only observed in IR condition (p<0.05), while post-exercise DM remained at pre-exercise baseline level in AR condition. Vc was significantly decreased at 1 and 2 hours post-exercise in both conditions (p<0.05 and 0.01, respectively). Mean heart rate at 1 hour post-exercise was found to be higher than resting baseline (p<0.05), indicating that some of the decrease in DL, DM and Vc might have been masked by the elevated cardiac output. The most significant finding was that the depressed post-exercise DM was recovered by an active recovery, giving stronger support for the presence of pulmonary edema during and after the sustained effort which was partially responsible for the reduction in DM following exercise. Changes of Vc were in identical pattern and similar magnitude in both AR and IR conditions, suggesting that the distribution of central blood volume due to gravity might have greater effect on post-exercise Vc than the shunting mechanism. This study represents the first attempt to examine the effect of active recovery on the post-exercise pulmonary diffusion capacity.

Thesis/Dissertation

application/pdf

2009-04-27

For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.

http://hdl.handle.net/2429/7621

Human Kinetics

University of British Columbia

UBCV

DSpace