Process evaluation of the receipt of an exercise intervention for fatigued employees: the role of exposure and exercise experiences

Work-related fatigue among employees is related to negative consequences. Therefore, it is valuable to evaluate interventions that potentially reduce fatigue and increase health and well-being among these employees. The present study investigated whether variations in the receipt of an exercise intervention for fatigued employees were related to intervention effectiveness. We investigated (a) whether exposure to the exercise intervention was related to differences in employees’ health and well-being trajectories throughout the intervention, (b) the amount of exposure that is minimally required before health and well-being effects become visible, and (c) whether exercise experiences (pleasure, psychological detachment, and effort) were related to differences in health and well-being trajectories throughout the intervention. Fatigued employees were randomly allocated to a 6-week exercise intervention (n = 49) or a wait list (n = 47). Participants were measured before, 5 times during, and at the end of the intervention concerning health and well-being indicators (all participants) and exercise experiences (only exercisers). Latent growth curve modelling showed that sufficient exposure and optimal exercise experiences contribute to the success of an exercise intervention for fatigued employees. Furthermore, it was shown that health and well-being effects of exercise are visible early in time.