Post-Metabolic Response To Exercise In Normobaric Hypoxia

The purpose of the study was to examine post‐metabolic response to constant workload exercise (CWE) under normobaric hypoxia. Seven active healthy males (age: 26±4 yrs; height: 176±4 cm; weight: 78±10 kg; BMI: 25±3 kg•m −2 ; VO 2max : 4.0±0.3 L•min −1 ) randomly underwent normoxic and hypoxic (F i O 2 = 0.15) CWE. Each experimental session consisted of a basal metabolic rate determination (BMR), 60‐min of CWE, and 60‐min of post‐exercise metabolic rate measurement. For each condition, 24‐hr post‐treatment BMR was recorded. Absolute workload was determined during a graded cycling test in normoxia and set at 50% of participants’ peak power (314±26 W) for both conditions. There was a significant condition/time (0–20; 21–40, and 41–60‐min) interaction on post‐exercise lipid metabolism ( p = 0.015). Fat contribution was 47±19%, 60±9% and 51±12% in normoxia; and 79±20%, 79±19% and 62±24% in hypoxia, for each epoch, respectively. Although not statistically significant, fat contribution 24‐hrs after the hypoxic intervention was elevated 3% above baseline. In conclusion, exercise in hypoxia contributed to an increase reliance on fat oxidation post‐treatment up to 24‐hrs. This result was explained by higher glycolytic flux during exercise under hypoxia compared to normoxia at the same absolute workload.