Key result
Repeated double-poling sprint exercise in normobaric hypoxia significantly increased exercise-induced deoxygenated hemoglobin (241.7% vs 175.8%) and total hemoglobin compared to normoxia.
Why the study?
The study was conducted to compare upper-limb muscle oxygenation responses during repeated double-poling sprint exercise in normobaric hypoxia versus normoxia.
Does repeated double-poling sprint exercise in normobaric hypoxia alter muscle oxygenation and power output compared to normoxia in trained male kayakers?
RCT (n=8)
Single-blind
Randomized
No
Does repeated double-poling sprint exercise in normobaric hypoxia alter muscle oxygenation and power output compared to normoxia in trained male kayakers?
Absolute Event Rate: 241.7% vs 175.8%
p-value: p=<0.05
Moderate hypoxia during repeated sprint exercise of the upper limbs augments muscle blood perfusion without significantly impairing power output.
Hypoxia may enhance muscle deoxygenation during sprint exercise; hypothesis-generating for training protocols and requires confirmation in performance trials.
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 (82.9 ± 0.9% vs. 90.5 ± 0.8%) and systemic oxygen uptake (1936 ± 140 vs. 2408 ± 83 mL∙min-1) values were lower (P < 0.05). Exercise-induced increases in deoxygenated hemoglobin (241.7 ± 46.9% vs. 175.8 ± 27.2%) and total hemoglobin (138.0 ± 18.1% vs. 112.1 ± 6.7%) 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.
No takes yet. Share an insight, caveat, or question.
Yamaguchi et al. (2019) conducted an RCT in Healthy trained sprint kayakers (n=8). Normobaric hypoxia (FiO2 = 14.5%) vs. Normoxia (FiO2 = 20.9%) was evaluated on Exercise-induced increase in deoxygenated hemoglobin (%) (p=<0.05). Repeated double-poling sprint exercise in normobaric hypoxia significantly increased exercise-induced deoxygenated hemoglobin (241.7% vs 175.8%) and total hemoglobin compared to normoxia.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: