Revising on the run or studying on the sofa: prospective associations between physical activity, sedentary behaviour, and exam results in British adolescents

Table 1 Participant characteristics. Values are Mean(SD) unless otherwise stated

	All	Boys	Girls	p value for difference
	(n = 845)	(n = 368)	(n = 477)	p value for difference
Demographic variables
Age	14·5 (0·5)	14·5 (0·5)	14·6 (0·5)	0·04
BMI z-score	0·20 (1·06)	0·19 (1·08)	0·20 (1·04)	0·83
Deprivation rank	24,455 (1199, 32319)	24,4890 (6098, 32319)	24,455 (1199, 32319)	0·20^a
MFQ	13 (8–20)	11 (7–17)	15 (8–23)	<0·001^a
Objective sedentary (mean hr/day)
Sedentary	6·1 (2·1)	5·6 (2·0)	6·5 (2·1)	<0·001
Objective physical activity (median (IQR) min/day)
MVPA	38·8 (19·7-65·1)	56·4 (31·2- 82·9)	28·0 (14·0- 48·6)	<0·001^a
Self-reported sedentary (median (IQR) hr/day)
Combined variables
Screen time	4·0 (2·8-5·5)	4·3 (3·1-5·7)	3·7 (2·6-5·1)	<0·001^a
Non screen sedentary	1·5 (1·0-2·3)	1·3 (0·7-2·0)	1·6 (1·1-2·6)	<0·001^a
Individual variables
TV viewing	1·9 (1·2-2·7)	1·9 (1·3-2·9)	1·9 (1·1-2·7)	0·436^a
Internet Use	1·3 (0·6-2·3)	1·1 (0·5-2·0)	1·6 (0·9-2·4)	<0·001^a
Computer Games	0·1 (0·0-0·9)	0·9 (0·3-1·6)	0·0 (0·0-0·1)	<0·001^a
Homework	1·0 (0·6-1·6)	1·0 (0·6-1·3)	1·2 (0·8-1·8)	<0·001^a
Reading	0·3 (0·0-0·8)	0·2 (0·0-0·6)	0·5 (0·0-0·8)	<0·001^a
Academic achievement
Total points¹	416·6 (117·5)	394·1 (115·1)	434·0 (116·6)	<0·001

^aWilcoxon-Mann–Whitney test
¹Calculated to include GCSE and GNVQ results e.g., for GCSEs A* = 58, A = 52…G = 16, and similar for GNVQ grades

ISSN: 1479-5868