Gender influences physical activity changes during adolescence: The HELENA study

Background: We compared differences in physical activity (PA) between pre/mid-pubertal and post-pubertal participants according to gender. Methods: The study included a total of 1842 healthy participants aged 12.5-17.4 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) study. Participants wore a uniaxial accelerometer (ActiGraph(C) GT1M, Pensacola, FL, USA) attached to their lower back for seven consecutive days to measure PA. Pubertal status was assessed by physical examination and the population was classified as pre/mid-pubertal (Tanner stages 1-3) or post-pubertal (Tanner stages 4-5). PA was compared between these groups according to gender during the whole week, on school-free days and on school days, before and after school, and during lessons and recesses. Results: When comparing the pre/mid-pubertal group with the post-pubertal group, girls' total PA did not differ between groups. However, a slight difference was observed in boys, among whom PA on school-free days showed a difference of 17.6% between the pre/mid-pubertal group and the post-pubertal group (679 kcounts vs 564 kcounts, respectively; P = 0.0007) and 20% (162 kcount vs 135 kcounts; P = 0.006) for school recess. There was no difference among girls. Conclusions: A reduced level of PA in the post-pubertal groups was only observed in boys during nonorganized times such as on school-free days and during school recesses, with a moderate impact on total PA. (C) 2019 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.