Cross-sectional associations of weekly time, social context, and motivation of exercise with mental health among workers

Purpose Exercise is considered a strategy to promote mental health among workers. However, the optimal exercise conditions that promote mental health benefits for workers are still unclear. This study examined the cross-sectional associations of weekly exercise time duration, social context of exercise, and exercise motivation levels with the mental health among Japanese workers. Methods A web-based cross-sectional questionnaire survey was conducted among 18,902 workers, aged 20–59 years. The mental health variables (psychological distress, psychological stress reaction, physical stress reaction, job satisfaction, and work engagement), exercise participation (non-exercisers, exercisers), and demographic factors of all responders were measured. Weekly exercise time, social context of exercise (alone only, with others only, both alone and with others), and exercise motivation (non-regulation, external/introjected regulation, identified regulation, integrated regulation, and internal regulation) were also measured amongst exercisers. After adjusting for demographic factors, multiple regression analyses were conducted. Results Exercisers had significantly lower psychological distress, lower psychological and physical stress reactions, higher job satisfaction, and higher work engagement than non-exercisers. Among exercisers, while weekly exercise time duration and social context of exercise were not clearly and robustly associated with mental health variables, respondents with intrinsic regulation had significantly lower psychological distress, lower psychological and physical stress reaction, higher job satisfaction, and higher work engagement than those with lower self-determined motivations. Conclusions This study found that more self-determined exercise motivation is closely associated with advantageous mental health variables, than the duration or the social context of exercise among Japanese workers.