High Intensity Interval or Moderate Continuous Training in Health Indicators of Adolescents with Central Obesity

PURPOSE: To evaluate the effects of HIIT and moderate intensity continuous training (MICT) on health indicators from adolescents with central obese. METHODS: This is a randomized clinical trial, with three evaluations: baseline, after 8 and after 16 weeks. The sample was composed by 42 participants, randomized in two groups: HIIT (n = 22) and a MICT (n = 20). After 16 weeks of training (3 sessions/week), 34 adolescents finished the program (HIIT, n = 21; MICT, n = 13). The HIIT group performed different models of interval training, progressively organized, and the MICT trained in a fixed intensity from 60 to 80% of HRmax. Anthropometrical data ([BMI, Waist Circumference [WC], Height Waist Ratio [HWR], Body Fat Percentage [%BF]), cardiorespiratory fitness (CRF), blood pressure (systolic and diastolic) and metabolic profile (fasting blood glucose [FBG], high density lipoproteins [HDL-C], low density lipoproteins [LDL-C], total cholesterol, non-HDL cholesterol and triglycerides [TG]) were analyzed. RESULTS: Sixteen weeks of aerobic training resulted in significant reductions in BMI (HIIT = -4.5% [ES = -0.26] vs MICT = -3.9% [ES = -0,24]), WC (HIIT = -6.9% [ES = -0.64] vs MICT = -6.6% [ES = -0.61]), HWR (HIIT = -10.5% [ES = -1.00] vs MICT = -5.2% [ES = -0.50]), %BF (HIIT = -14.3% [ES = -0.59] vs MICT = -9.8% [ES = -0.40]), FBG (HIIT = -6.1% [ES = -0.65] vs MICT = -11.1% [ES = -0.89]) and non HDL cholesterol (HIIT = -14.5% [ES = -0.44] vs MICT = -11.0% [ES = -0.37]), and increased CRF (HIIT = 13.0% [ES = 1.77] vs MICT = 10.3% [ES = 0.76]). Only HIIT improved diastolic blood pressure (-17.0%, ES=-0.87), LDL-C (-13.3%, ES=-0.34) and total cholesterol (-11.9%, ES = -0.47), but only MICT changed positively TG (-23.4%, ES = -0.44). No changes were observed for systolic blood pressure and HDL-C. No differences were found in all variables between groups. Relating to inadequacy cases, both groups changed TG (HIIT = 20 to 11, MICT 13 to 6), but only HIIT decreased the number of adolescents in inadequacy from CRF and blood pressure (from 14 to 3). CONCLUSIONS: 16 weeks of HIIT or MICT positively impact anthropometrical variables, metabolic profile and CRF in obese adolescents.