Table 1

Age, sex and type of school for the children participating by study year

	Study year 1 (2011–2012) (N = 1015)		Study year 2 (2012–2013) (N = 1179)		Study year 3 (2013–2014) (N = 1077)
	Number of children	% girls	Number of children	% girls	Number of children	% girls
Age 8	50	54%	−	−	−
Age 9	197	61%	69	55%	−
Age 10	213	50%	236	58%	68	57%
Age 11	224	50%	271	51%	233	59%
Age 12	225	52%	270	47%	244	52%
Age 13	103	49%	218	57%	226	45%
Age 14	3	33%	112	47%	199	53%
Age 15	−	−	3	33%	106	48%
Age 16	−	−	−	−	1	0%
I-school/c-schoola	602/413	56%/47%	800/518	56%/47%	767/440	55%/48%

^aI-school: intervention school, 6 h PE per week

C-school: control school, 2 h PE per week