Serving on empty: A multi‐level diary study on the dynamics of volunteer engagement in nonprofit sport clubs

We conducted a multilevel diary study in non‐profit sports clubs in Germany to examine the within‐person (day‐level) dynamics of volunteer engagement. The study was pre‐registered at OSF ( Link_to_Preregister ). Over a 3‐week period, we collected 649 usable daily reports from 105 participants ( M = 6.18 days per person). Multilevel analyses showed that self‐determined motivation was positively related to perceptual volunteer engagement (PVE). In turn, PVE was positively associated with time spent volunteering, both formally and informally. Moreover, athlete mental fatigue significantly weakened the positive association between self‐determined motivation and PVE. In contrast, volunteering flexibility did not moderate the relationship between self‐determined motivation and PVE. Overall, these findings advance theoretical understanding of the day‐to‐day mechanisms underlying volunteer engagement in nonprofit sports clubs and have important practical implications for their management.