Acute effects of high-intensity interval training and moderate-intensity continuous training sessions on cardiorespiratory parameters in healthy young men

Purpose: The aim of the present study was to compare the energy expenditure (EE) during and after two treadmill protocols, high-intensity interval training (HIIT) and moderate continuous training (CONT), in young adult men. Methods: The sample was comprised by 26 physically active men aged between 18 and 35 years engaged in aerobic training programs. They were divided into two groups: HIIT (n = 14) which performed eight 20 s bouts at 130% of the velocity associated with the maximal oxygen consumption on a treadmill with 10 s of passive rest, or CONT (n = 12) which performed 30 min running on a treadmill at a submaximal velocity equivalent to 90–95% of the heart rate associated with the anaerobic threshold. Data related to oxygen consumption (V˙ O ₂) and EE were measured during the protocols and the excess post-exercise oxygen consumption (EPOC) was calculated for both sessions. Results: No difference was found between groups for mean V˙ O ₂ (HIIT: 2.84 ± 0.46 L min⁻¹; CONT: 2.72 ± 0.43 L min⁻¹) and EE per minute (HIIT: 14.36 ± 2.34 kcal min⁻¹; CONT: 13.21 ± 2.08 kcal min⁻¹) during protocols. Regarding total EE during session, CONT resulted in higher values compared to HIIT (390.45 ± 65.15; 55.20 ± 9.33 kcal, respectively). However, post-exercise EE and EPOC values were higher after HIIT (69.31 ± 10.88; 26.27 ± 2.28 kcal, respectively) compared to CONT (55.99 ± 10.20; 13.43 ± 10.45 kcal, respectively). Conclusion: These data suggest that supramaximal HIIT has a higher impact on EE and EPOC in the early phase of recovery when compared to CONT.