Effects of five weeks of self-paced and prescribed high-intensity interval exercise on perceptual responses, body composition, aerobic capacity, blood glucose, and lipid profile in overweight-to-obese adults

Background: Evidence has shown that when overweight/obese individuals are permitted to self-pace their exercise intensity during a continuous exercise, it tends to generate a greater positive affective response (pleasurable) compared to the prescribed-based exercise, but these have yet to be explored in the context of high-intensity interval exercise (HIIE) in overweight and obese adults. We examined the health parameters (body composition, aerobic capacity, blood glucose, total cholesterol, triglyceride, HDL, and LDL) and perceptual responses (affective, enjoyment and perceived exertion) during prescribed HIIE (P-HIIE) and self-paced HIIE (S-HIIE) across a 5-week exercise intervention in overweight and obese adults. Methods: Twenty inactive men and women (mean ± SD; aged 26.7 ± 4.9 years old; BMI = 27.5 ± 4.2; PA levels = 482 ± 333 MET-min/week) were randomized to 5 weeks of P-HIIE (n=10; 6-8 × 1-min work-intervals at 90% of maximal aerobic speed) or S-HIIE (n=10; 6-8 × 1-min work-intervals at self-paced intensity), both for three days in a week (15 sessions in total). Perceptual responses observed in session 1, session 8, and session 15 were analyzed. Whereas health parameters were measured before and after 5 weeks exercise intervention. Results: P-HIIE group elicited lower affective responses across all work interval compared to S-HIIE group in session 1 (all P< 0.03, all ES> 0.66). Both groups generated greater post-enjoyment in session 8 and session 15 compared to session 1 (all P< 0.02, all ES> 0.60). Also, both P-HIIE and S-HIIE groups produced an enhancement in aerobic capacity (P0.71), but no significant between-group differences in the change of the pre- and post-measures of health markers. Conclusion: S-HIIE and P-HIIE protocols produce a comparable effect of perceptual responses and aerobic capacity over a 5-week exercise intervention in the overweight and obese cohort, indicating the viability and adoption of this protocol for health promotion in overweight and obese adults.