Table 1.

Basic descriptive statistics of the study participants (N = 4352)

Study variables	Total (N = 4352)	Boys (N = 1471)	Girls (N = 2881)	p for sex
	Mean ± SD	Mean ± SD	Mean ± SD
Age (years)	12 ± 1	12 ± 1	12 ± 1	0.890
Height (cm)	156 ± 10	159 ± 11	155 ± 10	< 0.001
Weight (kg)	47 ± 11	49 ± 13	46 ± 10	< 0.001
Body-mass index (kg/m2)	19 ± 3	19 ± 3	19 ± 3	0.756
6MWT (m)	561 ± 93	576 ± 93	545 ± 92	< 0.001
Speed (m/min)	94 ± 5	98 ± 5	91 ± 6	< 0.001

p < 0.05