Fig. 1

Years of physical education exposure in the CHAMPS-study DK cohort by school-year at baseline and intervention status (2008–2015), Grey boxes indicate six weekly lessons of physical education. Dark boxes indicate two weekly lessons. The NSR mandates 45 min of physical activity on each school-day (not including recess and other breaks). Implementation of the 45 min is managed at the school-level. PE: Physical education, NSR: national school-reform