Table 3.

Minimally adjusted analyses between PA and body composition

Outcome	Activity	Sex	β	95% CI	P	P (Sex dif)
Fat mass	Light	Male	0.028	(−0.030, 0.086)	0.3484	0.6110
		Female	0.006	(−0.052, 0.065)	0.8293
		All	0.015	(−0.026, 0.056)	0.4697
	Moderate	Male	−0.055	(−0.110, −0.001)	0.0463	0.1818
		Female	−0.009	(−0.050, 0.032)	0.6663
		All	−0.025	(−0.058, 0.008)	0.1335
	Vigorous	Male	−0.077	(−0.122, −0.033)	0.0007	0.1689
		Female	−0.033	(−0.078, 0.013)	0.1592
		All	−0.060	(−0.091, −0.028)	0.0002
Lean mass	Light	Male	0.018	(−0.014, 0.050)	0.2644	0.1712
		Female	0.050	(0.018, 0.082)	0.0024
		All	0.035	(0.013, 0.058)	0.0023
	Moderate	Male	0.009	(−0.021, 0.039)	0.5730	0.2592
		Female	−0.013	(−0.036, 0.010)	0.2591
		All	−0.006	(−0.024, 0.012)	0.5429
	Vigorous	Male	0.025	(0.001, 0.050)	0.0452	0.1907
		Female	0.049	(0.024, 0.074)	0.0001
		All	0.038	(0.020, 0.055)	0.0001

The association of light, moderate, and vigorous activity on fat mass (log) and lean mass, adjusted for age, height, average recording time, and other levels of exercise intensity in boys (n = 778) and girls (n = 970). β coefficients represent sd change in fat per lean mass per sd increase in light activity and per doubling in moderate or vigorous activity. P values are shown for sex-specific and combined association and the difference between sexes (sex interaction). Bold values indicate combined results.