Relation between levels of physical activity and body fat in 9 to 12 years old Greek boys

Aim. The purpose of the present study was to investigate the relationship between habitual daily physical activity and levels of body fat in Greek elementary school children. Methods. The sample consisted of 254 boys, 9-12 years old. Body fat was estimated by age-related body mass index (BMI), waist-to-hip-ratio (WHR), triceps and calf skinfolds and bio-electrical impedance analysis. Physical activity was assessed by the Self-Administered Physical Activity Checklist and an activity accelerometer, worn by 40 children, for three days. The children were grouped into two categories based on their BMI: overweight/obese and normal-weight Results. Overweight and obese boys had lower levels of physical activity compared to normal-weight boys. Physical activity, assessed by the activity monitors, was significantly correlated with BMI (r = -0.51, P<0.()1), percentage body fat (r = -0.57, P<0.01), hip circumference (r = -0.50, P<0.01) and sum of two skinfolds measured (r = -0.60, P<0.01). Total minutes of physical activity and weighted activity MET score, as assessed by the questionnaire, showed small but statistically significant negative correlations with all adiposity measurements. In addition, minutes in sedentary pursuits were positively correlated with BMI (r =0.13, P<0.05), waist circumference (r =0.15, P<0.05) and hip circumference (r =0.12, P<0.05). Conclusion. This study shows that high levels of body fat are associated with low levels of physical activity and increased time of sedentary activities, in a Greek sample of 9 to 12 years old boys.