Vascular function responses to resistance exercise followed by intermittent hypoxic exposure in untrained males

This study investigated whether intermittent hypoxic exposure following resistance exercise mitigates acute vascular dysfunction. The main objective was to assess the effects of post-exercise hypoxia on flow-mediated dilation (FMD), blood pressure, and brachial-ankle pulse wave velocity (baPWV) in untrained males.

Thirteen untrained male university students (age: 20.46 ± 0.87 years; body mass index: 23.6 ± 0.67 kg/m²) participated in a crossover trial involving three experimental conditions: (1) resistance exercise followed by normoxia (RE, FIO₂ = 21%), (2) resistance exercise followed by intermittent hypoxia (RE-H1, alternating FIO₂ = 13.6% and 21%), and (3) resistance exercise followed by mild intermittent hypoxia (RE-H2, alternating FIO₂ = 15.8% and 21%). Participants performed five sets of 10 leg extensions at 70% of their one-repetition maximum. FMD, blood pressure, and baPWV were measured at baseline and 0, 10, 20, 30, and 60 min post-exercise.

Post-exercise systolic blood pressure decreased in all conditions (p < 0.05), with no significant differences between conditions, while diastolic blood pressure showed no significant changes (p > 0.05). baPWV decreased in RE and RE-H2 (p < 0.05) but not in RE-H1, with RE showing greater reductions than RE-H1 (p < 0.05). Blood flow and shear rates increased in all conditions (p < 0.05), with greater responses in RE-H1 and RE-H2 (p < 0.05). FMD decreased after RE (p < 0.05) but was maintained in RE-H1 and RE-H2 for 60 min post-exercise. The %FMD/Δ shear rate remained consistently higher in RE-H1 and RE-H2 than in RE throughout the post-exercise period (p < 0.05).

Intermittent hypoxia following resistance exercise appears to preserve endothelial function and prevent transient vascular impairment, suggesting its potential as a recovery-enhancing strategy.