Table 1 Descriptive statistics of included variables by measurement point

Respondent age

13

14

15

16

18

19

21

23

30

40

N

924

958

936

789

779

643

634

630

536

455

Coding of time in LCGA

-10

-9

-8

-7

-5

-4

-2

0

7

17

LVPA (0–7)

 n

912

952

945

708

777

639

583

628

533

447

 Mean

3.18

3.11

3.00

2.55

2.24

2.11

2.02

1.88

1.70

1.99

 S.E

0.07

0.07

0.07

0.08

0.08

0.08

0.08

0.08

0.07

0.08

Membership in sports clubs (No [0], Yes [1])

 n

913

953

940

708

776

628

533

447

 Percentage member

65.4

62.4

58.5

52.2

38.8

26.8

23.1

30.5

Diversity in leisure-time activities

 n

927

627

452

 Mean

13.57

9.02

7.57

 S.E

0.21

0.18

0.16

Outdoor recreation, summer (0-4)

 n

917

949

946

703

628

533

446

 mean

3.30

3.12

3.30

2.99

2.84

2.92

3.01

 S.E

0.03

0.03

0.03

0.04

0.04

0.04

0.04

Outdoor recreation, winter (0-4)

 n

915

949

945

704

628

534

443

 mean

2.94

2.55

2.55

2.23

2.03

2.23

2.32

 S.E.

0.03

0.03

0.04

0.04

0.04

0.04

0.05

Number of active friends (0–4)

 n

904

934

772

 Mean

3.16

2.75

2.15

 S.E

0.04

0.04

0.05

Best friend’s activity level (0–4)

 n

878

934

626

 Mean

2.65

2.58

1.93

 S.E

0.04

0.04

0.05

Gender (Boy [0], Girl [1])

 n^a

1103

 Percentage of girls

45.6

BMI

 n

886

606

443

 Mean

20.18

23.28

25.52

 S.E

0.08

0.15

0.18

Having children (No [0], Yes [1])

 n

585

628

536

449

 Percentage having children

7.0

16.4

55.0

85.3

Income (2000: 1–6; 2007: 1–8; 2017: 1–10)

 n

626

534

446

 Mean

1.66

3.78

6.45

 S.E

0.04

0.07

0.10