Flow is a rewarding psychological state that motivates individuals to repeat activities. This study explored healthcare workers’ flow experiences during a workplace exercise intervention. Seventy-nine females were assigned to either a 12-week football or Zumba exercise intervention and their flow experiences were assessed at the beginning, midway and at the end of the intervention. The results showed that both intervention groups experienced medium levels of flow and an increase in flow values over time. A significant positive correlation between experiencing flow midway through the intervention and adherence to regular physical activity 18 weeks after the end of the intervention was found. Furthermore, repeated measures throughout the intervention period showed a significantly different development of flow values over time for the adherers and nonadherers. Flow therefore may be of importance for adherence to regular workplace physical activity. Future research needs to investigate the importance of flow in other physical activity settings, especially also for male participants.