Hypoxic exercise at the same power output as normoxic exercise increased mean heart rate (154 vs 139 bpm, p<0.01) and delayed cardiac autonomic recovery.
Does hypoxic exercise alter cardiac autonomic and physiological responses compared to normoxic exercise in men?
Heart rate-matched hypoxic exercise yields similar cardiac autonomic responses to normoxic exercise despite lower mechanical load, whereas power-matched hypoxic exercise increases metabolic stress and delays autonomic recovery.
Absolute Event Rate: 154% vs 139%
p-value: p=<0.01
Abstract Exercise physiological responses can be markedly affected by acute hypoxia. We investigated cardiac autonomic and physiological responses to different hypoxic training protocols. Thirteen men performed three exercise sessions (5×5-min; 1-min passive recovery): normoxic exercise at 80% of the power output (PO) at the first ventilatory threshold (N), hypoxic exercise (FiO2=14.2%) with the same PO as N (HPO) and hypoxic exercise at the same heart rate (HR) as N (HHR). PO was lower in HHR (21.1±9.3%) compared to N and HPO. Mean HR was higher in HPO (154±11 bpm, p0.05) in HPO and HHR compared to N. HR recovery (HRR) and HR variability indices were similar in N and HHR (p>0.05) but reduced in HPO (p0.05) and increased in HPO (p0.05) and increased in HPO (p<0.01). Moderate HR-matched hypoxic exercise triggers similar cardiac autonomic and physiological responses to normoxic exercise with a reduced mechanical load. On the contrary, the same absolute intensity exercise in hypoxia is associated with increased exercise-induced metabolic stress and delayed cardiac autonomic recovery.
Fornasiero et al. (2019) studied this question. Hypoxic exercise vs. Normoxic exercise was evaluated on Mean heart rate (p=<0.01). Hypoxic exercise at the same power output as normoxic exercise increased mean heart rate (154 vs 139 bpm, p<0.01) and delayed cardiac autonomic recovery.