Infancy and childhood growth and physical activity in adolescence: prospective birth cohort study from Brazil

This is a prospective birth cohort study in Pelotas, Brazil, including 457 adolescents (mean age: 13.3？years) with weight and length/height data at birth, one, three and six months, one and four years of age. PA was measured using a GT1M Actigraph accelerometer, and expressed as (a) minutes per day spent on sedentary, light, moderate, vigorous and very-vigorous activities; (b) total counts per day.61.3% of the adolescents accumulated 60+ minutes of moderate-to-vigorous PA per day. Weight and length/height trajectories in infancy and childhood were similar between those classified as active or inactive at 13.3？years. However, those classified as inactive were heavier and taller at all ages; differences were statistically significant only in terms of length at three, six and 12？months.Weight gain in infancy and childhood did not predict variability in adolescent PA, but those active in adolescence showed somewhat smaller average gains in length in infancy. These findings suggest that PA may partially be sensitive to early hormonal programming, or that genetic factors may affect both early growth and later metabolism or predisposition for PA.