Acute Effects Of Two-level Controlled SpO2 Under Systemic Hypoxia On Metabolic And Hormonal Responses To Resistance Exercise

Objective:Examine the acute effects of controlled two-level sp02 under systemic hypoxia on metabolic and hormonal responses to resistance exercise.Method:Ten male subjects performed five sets of 10 repetitions of barbell back squat exercise at 70% of 1RM with 1-min rest between sets under normoxia (NR, Sp02= 98%) and two-level controlled Sp02 under systemic hypoxia (H1, Sp02=80%; H2, Sp02=90%). Blood lactate(LA), serum growth hormone (GH), epinephrine (E), testosterone, and cortisol concentrations were measured before normoxia or hypoxia exposures(prel),15 min after the exposures(pre2), immediately (T-0),15min(T-15) and 30min(T-30) after the exercises.Results:LA and GH significantly increased at T-0;, T-15:and T-,30 in all trials(p<0.05). Only LA of HI (p<0.05) was higher than NR; at T-0, and no significant differences were observed among three trials in GH. The mean values of E of H1 (p<0.01) and H2 (p<0.05) significantly increased at T-0 compared with Pre2 but not in-the-NR, and only E of H1 (p<0.05) was higher than NR at:T-0. T significantly increased at T-0 in all trials (p<0.05). C of.H1 (p<0.05) and-H2 (p<0.05) significantly increased at T-15 but not in the NR. No significant differences were observed among three trials in T and C.Conclusion:Moderate-intensity resistance exercise performed controlled two-level Sp02 under simulated hypoxia does not induce greater anabolic hormonal responses, but 80%Sp02 under simulated hypoxia caused greater metabolic response after moderate-intensity resistance exercise.