Correlation between physical activity measured by accelerometry and BMI in adolescents

Abstract

The aim of this study was to investigate the correlation between physical activity measured by accelerometry and excess weight in schoolchildren. Three hundred and ninety one school-age adolescents (10 to 18 years old) participated in the study. The cut-off points used to estimate time spent in physical activity were: moderate ?3.0 METs and vigorous ?6.0 METs. Student’s t-test and Pearson product-moment correlation coefficient were used to verify statistical differences and correlations between physical activity and body mass index (BMI). Statistical significance was set at p<0.05. Male schoolchildren spent more time in moderate (96.1 ± 39.6 min.day-1) and vigorous (9.7 ± 8.8 min.day-1) physical activity than their female peers (moderate: 73.7 ± 37.7 min.day-1; vigorous: 6.1 ± 6.8 min.day-1). For both sexes, younger schoolchildren (10 to 14 years old) were more physically active than older ones (14 to 18 years old). Time spent in moderate-vigorous physical activity was inversely related to BMI. These findings suggest that regular physical activity (RPA) is related to body weight reduction in schoolchildren. Therefore, RPA can be used as an obesity prevention strategy in elementary school.