Table 2 Descriptive statistics of the study sample of boys (N = 143) and statistical differences with girls

Age

13.40 ± 1.31

13.18 – 13.61

-.04

0.03

Ethnicity

Native Dutch

134 (93.7%)

Non-native Dutch

9

Academic year

Grade 7

73 (51.0%)

Grade 9

70

School level

Senior general secondary education

44 (30.8%)

University preparatory education

99

SES

Low-medium

32 (22.9%)

High

108

BMI (kg/m ² )

18.98 ± 2.81

18.51 – 19.45

−0.33

0.12

Depressive symptoms

9.12 ± 7.21

7.91 – 10.34

−3.63*

0.45

Total time spent moving per week (min.)

857.41 ± 222.09

817.60 – 897.21

48.10

0.22

Active commuting to school (min./week)

237.23 ± 96.89

221.21 – 253.24

13.68

0.14

Time spent moving per week corrected for active commuting to school (min.)

618.38 ± 203.59

581.89 – 654.88

32.66

0.17

Active commuting to school as % of total time spent moving per week

28.50 ± 10.60

25.86 – 29.67

0.74

0.07

D2 Test of attention

173.27 ± 26.74

168.82 – 177.72

−5.49

0.21

Symbol Digit Modalities Test

58.60 ± 10.87

56.74 – 60.46

−3.15*

0.30

Academic Achievement

6.62 ± 0.75

6.49 – 6.75

−0.44*

0.59

Mathematics performance

6.83 ± 1.11

6.65 – 7.02

−0.28*

0.26