Sample characteristics of boys and girls in the Northern Finland Birth Cohort 1986.

Low preference for active play was defined as parents reporting that children liked to participate in active play ‘hardly ever’.

Metabolic equivalent-hours based on the intensity and volume of physical activity divided into gender-specific quintiles: 1) active (two highest quintiles), 2) moderately active (third and fourth quintiles) and 3) inactive (lowest quintile).

Peak oxygen uptake (VO_2peak) in ml·kg⁻¹·min⁻¹ divided into gender-specific quintiles: 1) high (two highest quintiles), 2) average (third and fourth quintiles) and 3) low (lowest quintile).