Table 6 The intervention effect on cardiorespiratory fitness and muscle strength stratified by study arm and gender. The results are presented as mean differences in change (intervention arms vs controls) with 95% CI, P-values and ICC for school

 Cardiorespiratory fitness (m)

656

3.2 (−10.3, 16.8)

0.643

0.16

 Handgrip (kg)

698

−1.8 (−2.5, − 1.1)

< 0.001

0.24

 Standing broad jump (cm)

693

2.5 (0.1, 4.8)

0.036

0.04

 Sit-ups (n)

695

0.4 (−0.1, 1.0)

0.071

0.01

 Cardiorespiratory fitness (m)

612

−24.6 (−39.8, −9.3)

0.002

0.16

 Handgrip (kg)

648

−0.8 (−1.5, − 0.1)

0.039

0.24

 Standing broad jump (cm)

644

−1.1 (−3.7, 1.4)

0.380

0.04

 Sit-ups (n)

641

−0.2 (0.8, 0.3)

0.459

0.01

 Cardiorespiratory fitness (m)

677

36.7 (24.0, 49.3)

< 0.001

0.09

 Handgrip (kg)

723

−0.1 (−1.0, 0.7)

0.778

0.11

 Standing broad jump (cm)

720

1.3 (−1.7, 4.4)

0.401

< 0.01

 Sit-ups (n)

720

0.6 (0.1, 1.2)

0.040

0.07

 Cardiorespiratory fitness (m)

654

1.4 (−12.6, 15.5)

0.842

0.09

 Handgrip (kg)

697

−0.5 (−1.4, 0.3)

0.236

0.11

 Standing broad jump (cm)

689

1.2 (−2.0, 4.4)

0.464

< 0.01

 Sit-ups (n)

689

0.1 (−0.6, 0.6)

0.913

0.07