Oxygen Consumption in Nonexercising Muscle after Exercise

Little is known about the effect of exercise intensity on post-exercise oxygen consumption in nonexercising muscle. This study examined the effect of exercise intensity on muscle oxygen consumption (VO2mus) in nonexercising forearm flexor muscles (nonexVO2mus) after cycling exercise. Eight healthy male subjects performed 20 min of cycling exercise at 30%, 50%, and 70% of maximal oxygen consumption (%VO2max) on separate days. The nonexVO2mus values at rest, at the end of exercise, and during recovery after exercise were measured by near-infrared spectroscopy. VO2mus was determined using the rate of decrease in oxygenated hemoglobin during arterial occlusion. The nonexVO2mus at the end of exercise significantly increased by 1.3 +/- 0.1, 2.0 +/- 0.3, and 2.2 +/- 0.3-fold over resting values at 30%, 50%, and 70% VO2max, respectively. NonexVO2mus returned to the resting value after 3 - 5 min of recovery and then showed no significant change for 120 min after exercise at all exercise intensities. NonexVO2mus at the end of exercise at 70% VO2max was significantly higher than that after exercise at 30% VO2max. These results show that 20 min of cycling exercise induced an increase in nonexVO2mus and that higher intensity exercise produces a larger increase in nonexVO2mus after exercise.