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 3 Physical activity, sedentary behaviour, sleep duration and cardio-respiratory fitness at weekdays and weekend days at three seasons in 8–11 year old Danish children

Variables	n		Autumn			Winter			Spring
		Weekday	Weekend	Ratio⁵	Weekday	Weekend	Ratio⁵	Weekday	Weekend	Ratio⁵
Sedentary time (min/d)	635	467 ± 66	488 ± 88**	1.05	477 ± 61	509 ± 82**	1.07	459 ± 67	481 ± 94**	1.06
Screen-time (min/d)¹	704	120 (80;165)	210 (135;300)**
Screen-time (≤2 h/d)^1,2	704	46%	17%**
Total PA (cpm)	635	507 (417;614)	400 (295;514)**	0.84^a	464 (388;566)	347 (259;441)**	0.78^b	555 (450;671)	460 (331;635)**	0.92^c **
MVPA (min/d)	635	50 (34;71)	28 (16;47)**	0.68^a	46 (32;66)	24 (12;39)**	0.63^a	56 (38;78)	40 (21;62)**	0.83^b **
MVPA (≥1 h/d)³	635	37%	15%**	0.41	33%	9%**	0.28	45%	27%**	0.60 *
Sleep duration (min/night)⁴	523	559 ± 28	549 ± 48**	0.99	554 ± 31	549 ± 48*	1.00	543 ± 32	536 ± 55*	0.99

Abbreviations: PA Physical activity, MVPA Moderate-to-vigorous physical activity.
Data are presented as mean ± standard deviation or median (interquartile range) tested by student t-test or one-way ANOVA with post-hoc Bonferroni test (non-normal distributed data were transformed before analysis) or proportions (%) tested by Chi-square test. *, P < 0.05; **, P < 0.001. Different superscripts in a row (a,b,c) indicate significant difference (P ≤0.05).
¹Only measured at baseline.
²Screen time recommendations [23].
³Physical activity recommendations [17].
⁴Boys were sleeping 12, 11 and 13 min/night less during weekend days compared to weekdays in autumn, winter and spring (P < 0.001). Girls were not sleeping less during weekend days compared to weekdays (3, -4 and 0 min/night in autumn, winter and spring (P ≥ 0.22).
⁵Weekend day/weekday-ratio within season.

ISSN: 1471-2458