Sleep quality, sleep duration and physical activity in obese adolescents: effects of exercise training

Background: Decreased sleep duration and altered sleep quality are risk factors for obesity in youth. Structured exercise training has been shown to increase sleep duration and improve sleep quality. Objectives: This study aimed at evaluating the impact of exercise training for improving sleep duration, sleep quality and physical activity in obese adolescents (OB). Methods: Twenty OB (age: 14.5 +/- 1.5 years; body mass index: 34.0 +/- 4.7 kg m(-2)) and 20 healthy-weight adolescents (HW) completed an overnight polysomnography and wore an accelerometer (SenseWear Bodymedia) for 7 days. OB participated in a 12-week supervised exercise-training programme consisting of 180 min of exercise weekly. Exercise training was a combination of aerobic exercise and resistance training. Results: Sleep duration was greater in HW compared with OB (P < 0.05). OB presented higher apnoea-hypopnoea index than HW (P < 0.05). Physical activity (average daily metabolic equivalent of tasks [METs]) by accelerometer was lower in OB (P < 0.05). After exercise training, obese adolescents increased their sleep duration (+64.4 min; effect size: 0.88; P = 0.025) and sleep efficiency (+7.6%; effect size: 0.76; P = 0.028). Physical activity levels were increased in OB as evidenced by increased steps per day and average daily METs (P < 0.05). Improved sleep duration was associated with improved average daily METs (r = 0.48, P = 0.04). Conclusion: The present study confirms altered sleep duration and quality in OB. Exercise training improves sleep duration, sleep quality and physical activity.