The relation between physical activity and indicators of body fatness in Kenyan adolescents

Abstract

Physical activity (PA) behavior correlates with fatness in several distinct populations. Purpose: To determine the relationship between sedentary behaviour, PA and indices of body fatness in adolescents. Methods: Sedentary behaviour and habitual PA in 200 adolescents (102 girls and 98 boys) aged 13 – 16 years (13 ± 1 years; mean ± SD) were assessed by accelerometry for 5 consecutive days. Time in sedentary activities (<800 counts per minute (CPM) and light >800<3200 CPM), moderate >3200<82 00 CPM) and vigorous >8200 CPM) PA were calculated using Puyau cut - points. Indicators of body fatness were assessed using ∑skin - folds ( ΣSF) (triceps, biceps, sub - scapular and supra-iliac), Body Mass Index (BMI) and waist hip ratio (WHR) and correlated with sedentary and PA of different intensities. Results : Time in sedentary activity was positively correlated with BMI (r =0.44, P<0.001 ) and ΣSF (r = 0.21, P = 0.003). CPM and time spent engaged in light, moderate and vigorous intensity activities were negatively correlated with BMI and ΣSF. 16.1% of variation in ΣSF could be explained by gender; R 2 = 11.4% and time spent engaged in sedentary activities, R 2 = 4.7%; P<0.05. Conclusion: Time engaged in sedentary activity and PA was a significant predictor of in dices of adiposity in adolescents