Hypoxia Augments Oscillatory Blood Flow in Brachial Artery during Leg Cycling

• DOI: 10.1249/mss.0b013e31824294f9
• Publication Date: 2011-12-01T17:16:59Z
• Authors: ERIKA IWAMOTO; KEISHO KATAYAMA; YOSHIHARU OSHIDA; KOJI ISHIDA
• Keywords: Brachial artery; Hypoxia

Purpose The purpose of the present study was to elucidate changes in mean blood flow and oscillatory patterns inactive limb during leg cycle exercise hypoxia. We hypothesized that antegrade retrograde flows nonworking would increase incremental under hypoxic condition. Methods Eight males participated this study. Two maximal tests were conducted on a semirecumbent ergometer while subjects inhaled normoxic (inspired oxygen fraction [FIO2] = 0.21) or gas mixture (FIO2 0.12). began at an initial power output 30 W, workload increased by W every 2 min until exhaustion. Brachial artery velocity diameter simultaneously recorded using Doppler ultrasonography. Blood calculated cross-sectional area brachial time-averaged velocity. Results Mean decreased 120 both trials (P < 0.05), magnitude reduction not different between two trials. However, extent submaximal hypoxia greater than normoxia (normoxia vs hypoxia: 145.4 ± 10.3 172.4 9.0 mL·min−1 −89.1 4.9 −118.1 6.2 mL·min−1, P 0.05). Conclusions These results indicate has significant effect antegrade/retrograde cycling exercise.