Table 1.

Participation rates and missing cases.

	Class 1	Class 2
Total N in class	26	25
N attending regularly recess on this day of the week	26	19
N participating (positive consent)	25	18
Participation rate out of total N in class/attending recess	96%/96%	72%/95%
Missing self-reports	4	5
Missing sensors	6	7
Missing received nominations scores	1	5

Missing cases are defined as cases in which data were missing at least at one assessment.