Rating of Perceived Exertion and Serum Leptin Responses to Maximal Exercise in Obese Female Adolescents: Effects of Exercise Training Intensity

Abstract

Intensive exercise is one of the rarely used solutions to avoid obesity. This study aimed to examine the intensity effect [high-intensity interval training (HIIT) vs. moderate-intensity interval training (MIIT)] in severely obese female adolescents. Twenty one participants (age = 15.7 ± 0.9 years, percentage body fat (%BF) = 40.0 ± 1.5%) were assigned to HIIT: 100%; MIIT: 80% of Maximal Aerobic Speed (MAS) or control group (CG). Training program lasted 12 weeks, with sessions performed 3 times/week on the track. Running distances lasted 15 sec, interspaced with 15 sec active recovery. Body composition was assessed by Bioelectrical Impedance Analysis; blood pressure and rating of perceived exertion (RPE) were measured. Blood samples were collected at fast, and peak oxygen uptake (V̇O2peak) was measured breath-by-breath using a calibrated portable telemetric system. All values were taken before starting and after the last training session in the intervention. Both exercise training programs enhanced positively; body composition (body mass, BMI-Z-score, %BF), cardiovascular fitness (blood pressures, resting heart rate, V̇O2peak). Both exercise groups decreased plasma glucose (p 0.05), insulin (p 0.01 and p 0.05; HIIT and MIIT) and leptin (p 0.01). HIIT-group noted greater values in RPE score to maximal exercise (-29.0%, p 0.001) compared to MIIT-group (-14.9%, p 0.05). Overall, HIIT and MIIT induced beneficial changes in leptin sensitivity independently of exercise intensity. However, HIIT can be considered an efficient approach in decreasing the RPE score compared to MIIT, which may reduce the effort hardness and the drop-out from exercise in severely obese female adolescents.