Fig. 2.

Programme logic model of the Goldilocks-childcare randomised controlled trial. The dashed oblong represents the overall programme logic for the Goldilocks work principle. The golden box represents the input, the light blue boxes the intended steps at an organisational level, and the dark blue boxes the intended steps at an individual level. The black boxes illustrate the process evaluation. The middle row (Cardiorespiratory fitness) shows how the intervention will expectedly lead to improved cardiorespiratory fitness. The bottom row (Process evaluation) illustrates how the ‘black box’ between each step of the programme will be evaluated. Heart rate (HR) reserve is defined as the difference between the estimated maximal heart rate and the heart rate during sleep