Muscle oxygenation during repeated double-poling sprint exercise in normobaric hypoxia and normoxia

Abstract

We compared upper limb muscle oxygenation responses during repeated double-poling sprint exercise in normobaric hypoxia and normoxia. Eight male kayakers completed a repeated double-poling sprint exercise (3 × 3 × 20-s maximal sprints, 40-s passive recovery, 5-min rest) in either hypoxia (HYP, FiO2 = 14.5%) or normoxia (NOR, FiO2 = 20.9%). Power output, muscle oxygenation of triceps brachii muscle (using near infrared spectroscopy), arterial oxygen saturation, and cardiorespiratory variables were monitored. Mean power output tended to be lower (-5.2%; P = 0.06) in HYP compared with NOR, while arterial oxygen saturation (82.90.9% vs. 90.50.8%) and systemic oxygen uptake (1936140 vs. 240883 mLmin-1) values were lower (P 0.05). Exercise-induced increases in deoxygenated hemoglobin (241.746.9% vs. 175.827.2%) and total hemoglobin (138.018.1% vs. 112.16.7%) were greater in HYP in reference to NOR (P 0.05). Despite moderate hypoxia exacerbating exercise-induced elevation in blood perfusion of active upper limb musculature, power output during repeated double-poling exercise only tended to be lower.