Table 2. Associations of physical fitness^a at 6.6 yr (kindergarten) with body composition at 7.6 yr (school).

	Physical fitnessa at 6.6 yr
Cardiorespiratory fitness			Grip-to-BMI ratio		Grip-to-FFM ratio		SLJ-to-BMI ratio		SLJ-to-FFM ratio		Motor fitness		Balance
Body composition at 7.6 yr	β	P	β	P	β	P	β	P	β	P	β	P	β	P
BMI (kg/m2)
Unadjusted	-0.143	0.121	-0.091	0.320	-0.121	0.200	-0.515	<0.001	-0.442	<0.001	0.067	0.464	-0.282	0.002
Adjustedb	0.059	0.103	0.142	0.063	0.076	0.080	-0.332	0.005	-0.342	<0.001	0.032	0.098	-0.366	0.003
FMI (kg/m2)
Unadjusted	-0.200	0.029	-0.188	0.038	-0.162	0.085	.0.581	<0.001	-0.138	0.160	0.113	0.215	-0.251	0.005
Adjustedb	-0.018	0.002	0.080	0.001	0.028	0.003	-0.373	<0.001	-0.192	<0.001	0.057	0.001	-0.360	<0.001
FM (%)
Unadjusted	-0.213	0.020	-0.212	0.020	-0.161	0.087	-0.582	<0.001	0.006	0.952	0.120	0.188	-0.229	0.011
Adjustedb	-0.047	<0.001	0.045	<0.001	-0.009	<0.001	-0.373	<0.001	-0.166	<0.001	0.072	<0.001	-0.314	<0.001
FFMI (kg/m2)
Unadjusted	-0.036	0.695	0.050	0.586	-0.041	0.668	-0.302	<0.001	-0.498	<0.001	-0.005	0.956	-0.246	0.006
Adjustedb	0.132	0.438	0.166	0.364	0.108	0.457	-0.168	0.353	-0.399	<0.001	-0.009	0.542	-0.360	<0.001
WHtR
Unadjusted	-0.152	0.100	-0.305	0.001	-0.256	0.004	-0.508	<0.001	-0.381	<0.001	0.160	0.076	-0.247	0.006
Adjustedb	0.035	0.197	-0.257	0.045	-0.250	0.044	-0.391	0.003	-0.209	<0.001	0.185	0.091	-0.320	0.019

The results are presented as standardized regression coefficient (β), and P value are given for each association. P < 0.05 was considered statistically significant.

^aPhysical fitness was measured using 20 m shuttle run test (cardiorespiratory fitness), handgrip strength test (upper body muscular strength normalized to BMI and FFM: grip-to-BMI ratio, grip-to-FFM ratio, respectively), standing long jump test (lower body muscular strength normalized to BMI and FFM: SLJ-to-BMI ratio, SLJ-to-FFM ratio, respectively), 4×10 m shuttle run test (motor fitness) from the PREFIT battery, and one-leg stance test (balance) from EUROFIT battery.

^bAdjusted for maternal BMI, maternal educational attainment, child’s sex and age, at the measurements.

BMI—body mass index; FFM–fat-free mass; FFMI—fat-free mass index; FM—fat mass; FMI—fat mass index; WHtR–waist-to-height ratio.