Estimated Aerobic Capacity Changes in Adolescents with Obesity Following High Intensity Interval Exercise

Abstract

Vigorous aerobic exercise may improve aerobic capacity (VO_2max) and cardiometabolic profiles in adolescents with obesity, independent of changes to weight. Our aim was to assess changes in estimated VO_2max in obese adolescents following a 6-week exercise program of varying intensities. Adolescents with obesity were recruited from an American mid-west children’s hospital and randomized into moderate exercise (MOD) or high intensity interval exercise (HIIE) groups for a 6-week exercise intervention, consisting of cycle ergometry for 40 minutes, 3 days per week. Heart rate was measured every two minutes during each exercise session.  Estimated VO_2max measured via Åstrand cycle test, body composition, and physical activity (PA) enjoyment evaluated via questionnaire were assessed pre/post-intervention. Twenty-seven adolescents (age 14.7±1.5; 17 female, 10 male) completed the intervention. Estimated VO_2max increased only in the HIIE group (20.0±5.7 to 22.7±6.5 ml/kg/min, p=0.015). The HIIE group also demonstrated increased PA enjoyment, which was correlated with average heart rate achieved during the intervention (r=0.55; p=0.043). Six weeks of HIIE elicited improvements to estimated VO_2max in adolescents with obesity. Furthermore, those exercising at higher heart rates demonstrated greater PA enjoyment, implicating enjoyment as an important determinant of VO_2max, specifically following higher intensity activities.