Sex differences in physical activity (PA) through pubertal maturation and the growth spurt are often attributed to changing interests. The contribution of sex differences in biological maturation to the adolescent decline has received limited attention. This study examined the contribution of somatic maturation to sex differences in objective assessments of sedentary behavior and PA in Portuguese adolescents (N = 302, aged 13–16 years). Maturation was estimated from the percentage of predicted mature stature and physically active and inactive behaviors assessed with Actigraph GT1M accelerometers. The influence of age, sex and their interaction on body size, maturation and physical behaviors were examined using factorial ANOVA and, subsequently, ANCOVA (controlling for maturation) tested the effect of sex. Males spent more time in MVPA and less time in sedentary behavior than females. However, sex differences were attenuated when maturation was controlled; thus suggesting that maturity may play an important role in adolescent behaviors.
Rodrigues and Coelho e Silva are with the Faculty of Sport Sciences and Physical Education, University of Coimbra, Coimbra, Portugal. Mota is with the Faculty of Sport, Research Centre in Physical Activity, Health, and Leisure, University of Porto, Porto, Portugal. Cumming, Sherar, and Neville are with the School for Health, University of Bath, Bath, England, UK. Malina is with the Dept. of Kinesiology and Health Education, University of Texas at Austin and with Tarleton State University, Stephenville, TX.