Effects of Aerobic Exercise Training On Autonomic Nervous System Function In Obese Adolescents

Abstract

Aerobic exercise training is associated with improvements in autonomic nervous system function in adults, but little is known about the effect of exercise training on autonomic function in obese adolescents. PURPOSE: We tested the hypothesis that aerobic exercise training would improve autonomic nervous system function in obese adolescents. METHODS: Twenty obese male adolescents (age 13-14 yrs, body mass index 30±3kg/m2) were randomly assigned to an exercise training group (n=10) and a non-exercise control group (n=10). The subjects in the exercise training group performed supervised aerobic exercise programs with moderate intensity (RPE 11 - 13) for 12 weeks, 60 minutes per session, 3 times per week. Body composition, lipid profiles, blood pressure, and cardiorespiratory fitness were measured at baseline and after the 12 week intervention. The autonomic nervous system function was assessed using heart rate variability and the first one minute of heart rate recovery after exercise treadmill test. RESULTS: After 12 weeks, Body weight (87.1±13 to 84.2±12kg, p<0.001), waist circumference (99.8±7.4 to 94.9±8.1cm, p<0.001) and cardiorespiratory fitness (34.7±6.5 to 39.1±6.5ml/kg/min, p<0.001) were significantly improved in exercise group, but not the control group. Total power (2145±1242 to 3522±1615ms2, p=0.039), an index of parasympathetic nervous system function, and the first one minute of heart rate recovery after exercise treadmill test as an index of parasympathetic reactivation (22±7 to 27±6bpm, p=0.028) were significantly increased in the exercise group, but not the control group. CONCLUSIONS: These findings suggest that aerobic exercise raining improves the autonomic nervous system function in obese adolescents.