Comparison of acute cardiovascular and perceptual responses between moderateintensity interval and continuous exercise in inactive obese young adults
Authors: Phoemsapthawee Jatuporn ,   Department of Sports Science, Faculty of Sports Science and Health, Kasetsart University, Nakhon Pathom Province, Thailand, Sriton Bhuwanat , Tumnark Piyapon ,   Department of Sports Science, Faculty of Sports Science and Health, Kasetsart University, Nakhon Pathom Province, Thailand,   Department of Sports Science, Faculty of Sports Science and Health, Kasetsart University, Nakhon Pathom Province, Thailand
Published: July 2024

Background: Obesity dramatically elevates the risk of mortality and morbidity associated with cardiovascular disease (CVD). Obese people exhibit left ventricular structure abnormalities at an early age, in addition to having diminished resting systolic and diastolic function. Furthermore, there is evidence to suggest that autonomic dysfunction may play a role in the increased prevalence of CVD among obese individuals. Engaging in vigorous exercises may place excessive strain on the cardiovascular system, rendering it inappropriate for inactive, obese individuals. Objective: The crossover design with randomization study aimed to compare the immediate effects of moderate-intensity interval (MIIE) and continuous exercises (MICE) on hemodynamics, heart rate variability (HRV), affective, and enjoyment responses in young obese men. Materials and methods: A total of eighteen male participants, consisting of nine individuals with normal weight and nine individuals classified as obese, were involved in this study. The participants completed two 30-minute cycling protocols consisting of MIIE (3×5-minute at 90% ventilatory threshold; VT) interspersed with 3×5-minute active recovery cycling at 50% VT) or MICE at 70% VT with a 3-minute warm-up and cool-down at free load. Hemodynamic, HRV, enjoyment, and affective responses were measured at rest and at 5-, 10-, 15-, 20-, 25-, and 30-minute intervals during the exercise sessions of each protocol. Results: There were no significant differences in stroke volume index, cardiac index, ejection fraction, or systolic blood pressure between the MICE and MIIE protocols after each stage of the exercise protocols, both in normal-weight and obese participants. The MIIE protocol led to significantly lower ratings of perceived exertion (RPE) (p<0.05) and higher enjoyment (p<0.05) and affective responses (p<0.01) relative to MICE after each stage of exercise in obese participants. In addition, the MICE protocol led to a significantly lower standard deviation of normal-to-normal intervals (p<0.01) and a very low frequency (p<0.01) when compared to the MIIE in obese participants. Conclusion: Our study’s findings indicate that the MIIE and MICE protocols elicit similar cardiac responses in normal-weight and obese participants. Furthermore, the MIIE protocol results in significantly less RPE and exercise-induced fatigue and greater levels of enjoyment and affective response. The potential for heightened enjoyment and affective responses within the MIIE protocol may have significant implications for fostering exercise adherence among individuals with obesity.