Acute metabolic responses to high-intensity interval training in men with overweight or obesity: Does the exercise...

This study investigated the acute effects of two isoenergetic high-intensity interval exercise (HIIE) sessions, running (HIIE-RUN) and cycling (HIIE-BIKE), on post-exercise oxygen consumption ( ${\dot{V}}_{O_2}$ ), carbon dioxide production ( ${\dot{V}}_{C{O}_2}$ ), substrate oxidation and 24-h energy intake (EI) in men with overweight or obesity. Twelve fasted men (44.4 ± 14.5 years; body mass index: 28.3 ± 1.9 kg m^-2) completed both HIIE sessions. ${\dot{V}}_{O_2}$ and ${\dot{V}}_{C{O}_2}$ were measured before, during and after exercise, while substrate oxidation was calculated before and after exercise. The rate of perceived exertion was recorded during each exercise. Appetite was assessed throughout each session using a visual analogue scale (VAS) and EI was recorded via a 24-h dietary questionnaire. Both exercise modalities resulted in similar energy expenditure (EE), but HIIE-BIKE elicited a significantly higher respiratory exchange ratio (P = 0.002). No significant effect of exercise modality or time × modality interaction was observed for ${\dot{V}}_{O_2}$ and EE during the post-exercise period. Fat oxidation was significantly increased during recovery compared with the pre-exercise levels (P < 0.001), but did not differ between modalities. Appetite and 24-h EI were unaffected by the exercise modality. In men with overweight or obesity, isoenergetic HIIE-RUN and HIIE-BIKE seem to induce comparable post-exercise ${\dot{V}}_{O_2}$ , EE and substrate oxidation during the 2-h recovery period. Both modalities similarly promoted fat oxidation without specific dietary compensation observed.