Felipe Fossati Reichert, Jonathan Charles Kingdom Wells, Ulf Ekelund, Ana Maria Baptista Menezes, Cesar Gomes Victora and Pedro C. Hallal
Physical activity may influence both fat and lean body mass. This study investigated the association between physical activity in children between the ages of 11 and 13 years and both fat and lean mass.
A subsample of the 1993 Pelotas (Brazil) Birth Cohort was visited in 2004–2005 and 2006–2007. Physical activity was estimated through standardized questionnaires. Body composition (ie, fat and lean mass) was measured using deuterium dilution. Those with moderate-to-vigorous activity greater than 420 min/wk were classified as active, and physical activity trajectory was defined as being above or below the cutoff at each visit.
Four hundred eighty-eight adolescents (51.8% boys) were evaluated. The mean difference in fat mass in boys and girls who reported ≥ 420 min/wk of physical activity in both visits compared with those who were consistently inactive was –4.8 kg (P ≤ .001). There was an inverse association between physical activity and fat mass among boys in both crude and confounder-adjusted analyses, whereas for girls, the association was evident only in the crude analysis. There was no significant association between physical activity and lean mass.
Physical activity may contribute to tackling the growing epidemic of adolescent obesity in low- and middle-income countries.
Bruna Gonçalves Cordeiro da Silva, Fernando César Wehrmeister, Philip H. Quanjer, Rogelio Pérez-Padilla, Helen Gonçalves, Bernardo Lessa Horta, Pedro Curi Hallal, Fernando Barros and Ana Maria Baptista Menezes
The aim of this study was to evaluate the association between physical activity from 11 to 15 years of age and pulmonary function (PF) gain from 15 to 18 years of age among adolescents in a birth cohort in Brazil.
Longitudinal analysis of the individuals participating in the 1993 Pelotas Birth Cohort Study. Physical activity was assessed by self-report at ages 11 and 15, spirometry was performed at ages 15 and 18 (n = 3571). Outcome variables assessed were gains in forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC) and peak expiratory flow (PEF). Crude and adjusted linear regressions, stratified by sex, and mediation analyses were performed.
Boys who were active (leisure-time and total physical activity) at ages 11 and 15 had higher gains in FEV1, FVC, and PEF than those who were inactive. Vigorous-intensity physical activity in boys was also associated with FEV1 and FVC gains. Mediation analyses showed that height at age 18 accounted for 5% to 75% of the association between physical activity and PF gains. No significant associations were found among girls.
Physical activity in early adolescence is associated with gains in PF by the end of adolescence in boys.