Decreased muscle oxygenation and increased arterial blood flow in the non-exercising limb during leg exercise

Abstract

We evaluated arterial blood flow, muscle tissue oxygenation and muscle metabolism in the non-exercising limb during leg cycling exercise. Ten healthy male volunteers performed a graded leg cycling exercise at 0, 40, 80, 120 and 160 watts (W) for 5 min each. Tissue oxygenation index (TOI) of the nonexercising left forearm muscle was measured using a near-infrared spatially resolved spectroscopy (NIRSRS), and non-exercising forearm blood flow (NONEXFBF) in the brachial artery was also evaluated by a Doppler ultrasound system. We also determined O2 consumption of the non-exercising forearm muscle (NONEX : VO2mus) by the rate of decrease in O2Hb during arterial occlusion at each work rate. TOI was significantly decreased at 160 W (p < 0.01) compared to the baseline. The NONEX : VO2mus at each work rate was not significantly increased. In contrast, NONEXFBF was significantly increased at 120 W (p < 0.05) and 160W(p < 0.01) compared to the baseline. These results suggest that the O2 supply to the non-exercising muscle may be reduced, even though NONEXFBF increases at high work rates during leg cycling exercise. © Springer Science+Business Media, LLC 2010.