Faster Kinetics of V̇O2During Arm Exercise with Circulatory Occlusion of the Legs

Abstract
Occlusion of the nonworking leg muscles prior to the onset of supine arm exercise was examined for an effect on the kinetics of respiratory gas exchange (V̇O2 and V̇CO2), ventilation (V̇E), and heart rate (HR). Seven subjects performed arm cycling at 40 W (two females) or 50 W (five males) for 8 min following 4 min of “0” W pedaling. Six repetitions of each of uncuffed and cuffed leg conditions were averaged for individual subject analysis. The V̇O2 kinetics were significantly faster in the cuffed than the uncuffed condition (mean response time 66.0 ± 26.4 vs 81.2 ± 37.5 s, P < 0.04). The kinetics of V̇CO2, V̇E, and HR were not affected by occlusion. It is concluded that the faster V̇O2 kinetics with the prior occlusion of nonworking leg muscles was a consequence of increased availability of oxygen to the working arm muscles at the onset of exercise.