Longitudinal associations of physical activity and pubertal development with academic achievement in adolescents

•Boys with higher levels of moderate-to-vigorous physical activity had better academic achievement than those with lower levels of physical activity at baseline.•Physical activity was not associated with academic achievement at follow-up in boys or girls.•Continuously inactive adolescents had poorer academic achievement over the follow-up period than their more active peers.•Girls with more advanced pubertal status had better academic achievement than other girls.