Background: Post-exercise hypotension (PEH) is linked with the long-term reduction of blood pressure (BP), presenting potential benefits for managing hypertension while the impact of hypoxic exercise on PEH is still unclear. Purpose: This study aimed to investigate the impact of aerobic exercise under a hypoxic condition (FiO2: 14.9%) on the magnitude of PEH and to determine whether hypoxia induces an additive blood pressure lowering effect compared to exercise in normoxia. Method: This study employed a crossover design and involved 20 sedentary men who underwent exercise sessions under three conditions: hypoxic exercise (HYP) at 50% of peak power output (PPO), normoxic exercise (NOR) with the same mechanical intensity as HYP, and normoxic exercise (HRM) with physiological exercise intensity (heart rate; HR) matched to the HYP condition. Results: During the exercise, HYP and HRM induced higher HR, oxygen consumption, and minute ventilation responses compared to NOR (p < 0.05). Among the conditions, HYP showed the lowest ventilation efficiency (p < 0.01) and the most severe muscle and systemic hypoxemia (p < 0.01). Notably, only HYP induced a significant PEH (Mean Arterial Pressure: -6.9 mmHg at P15 compared to baseline; p < 0.01). Consequently, a significant increase in the diameter of the common femoral artery was observed at all time points during recovery in HYP (p < 0.05) and at 15min in HRM (p < 0.01). No significant differences in flow velocity, vascular conductance, and vascular resistance were observed across conditions. Conclusion: The findings suggest that hypoxic exercise significantly enhances PEH and induces greater arterial dilation of the exercise limbs compared to normoxic exercise, emphasizing its efficacy in hypertension management with lower mechanical stress. This underscores hypoxic training as a viable strategy for improving cardiovascular health, particularly beneficial for individuals with low fitness levels aiming to manage hypertension.
