Seasonal variation in objectively measured physical activity, sedentary time, cardio-respiratory fitness and sleep duration among 8–11 year-old Danish children: a repeated-measures study

Table 2 Physical activity, sedentary behaviour, sleep duration and cardio-respiratory fitness according to season of measurement in 8–11 year old Danish children

Variables	n	Autumn	Winter	Spring	ICC	Bias (%)	MAPE (%)
Sedentary time (min/d)	635	473 ± 63^a	486 ± 59^b	465 ± 66^a **	0.60	−0.4/2.5/-2.1	5.4/5.5/5.8
Screen-time (min/d)¹	704	146 (102;193)
Screen-time (≤2 h/d)^1,2	704	34%
Total PA (cpm)	635	490 ± 135^a	447 ± 120^b	557 ± 175^c **	0.47	−1.2/-9.9/11.1	11.6^a/13.1^b/15.1^c **
MVPA (min/d)	635	49 ± 23^a	44 ± 22^b	57 ± 27^c **	0.64	−2.0/-11.1/13.1	17.9^a/19.4^ab/21.1^b *
MVPA (≥1 h/d) (%)³	635	28%	22%	39% **
CRF (ml/kg/min)⁴	492	47.5 ± 5.1^a	48.3 ± 5.4^ab	49.2 ± 5.8^c **	0.74	−1.6/-0.1/1.7	3.7^a/3.2^b/3.9^a *
Sleep duration (min/night)	523	556 ± 27^a	553 ± 28^a	541 ± 30^b **	0.50	1.2/0.5/-1.6	2.3^a/2.2^a/2.7^b **

Abbreviations: ICC Intraclass correlation coefficient, MAPE Mean absolute percentage error, PA Physical activity, MVPA Moderate-to-vigorous physical activity, CRF Cardio-respiratory fitness.
Data are presented as mean ± standard deviation or median (interquartile range) tested using one-way ANOVA with post-hoc Bonferroni test (non-normal distributed data was transformed before analysis) or proportions (%) tested using Pearson’s chi-squared test.
*, P < 0.05; **, P < 0.001. Different superscripts in a row (a,b,c) indicate significant differences (P <0.05).
¹Only measured at baseline.
²Screen time recommendations [23].
³Physical activity recommendations [17].
⁴Distance run in the CRF-test at autumn, winter and spring were 973, 996 and 1023 meters, respectively.

ISSN: 1471-2458