Relationship between physical activity, sedentary behaviour and body composition among 11-13 year-old adolescent girls in Colombo

Abstract

INTRODUCTION AND OBJECTIVES: Physical activity (PA) is essential in reducing the risk of obesity. This study aimed to identify the relationship between the intensity of PA and body composition among 11-13 year-old adolescent girls from Colombo, Sri Lanka. METHODS: This is part of a larger study. A purposive sample of 46 adolescent school girls were recruited from the Colombo Municipal Council area. Time spent on light (LPA), moderate (MPA), vigorous (VPA), moderate-to• vigorous (MVPA) PA and sedentary behaviour were determined by waist-worn accelerometers (Actigraph• WGT3X-BT). Deuterium dilution (gold standard) was used with Fourier Transform Infrared (Agilent 4500®) spectroscopy to assess fat mass (FM) and fat-free mass. The% FM cut-off of 33.7% for Sri Lankan children was used to categorize the sample into high fat (HF) and normal fat (NF) groups. RESULTS: The mean age was 12.3 ± 1 year. %FM was significantly correlated with sedentary behaviour (r = 0.65, p < 0.001) and negatively correlated with'Mvf'A duration (r = -0.4, p < 0.01). Time spent on VPA (15.8 ± 6.7 min/day vs. 7.6 ± 3.2 min/day) and MVPA (33.9 ± 13.3 min/da vs. 15.5 ± 7.5 min/day) were significantly (p <0.01) higher among the NF group compared to the HF group. The NF group had significantly (p < 0.01) lower sedentary behaviour (379.7 ± 135 min/day vs. 622.7 ± 105.3 min/day) compared to the HF group. CONCLUSION: %FM was higher among the adolescent girls who spent more time in sedentary behaviours and among those who spent less time engaged in MVPA