The benefits of sustained leisure-time physical activity on job strain.

Background: The long-term effects of leisure-time physical activity (LTPA) on job strain have not been assessed in a large prospective population-based cohort study.

Objective: To examine the relationship between the LTPA and the prevalence of job strain.

Methods: The participants were 861 full-time employees (406 men and 455 women), aged 24-39 years in 2001, from the ongoing Cardiovascular Risk in Young Finns Study. LTPA was assessed using a self-report questionnaire in 1992 and in 2001. The participants were grouped into four categories according to tertiles of LTPA index at two time points: persistently active, increasingly active, decreasingly active and persistently inactive. Job strain was measured in 2001 by indicators of job demands and job control.

Results: Baseline LTPA was inversely associated with job strain (P < 0.001) and job demands (P < 0.05) and directly associated with job control (P < 0.05) in both sexes in a model adjusted for the change in 9-year LTPA, age, educational level, occupational status and smoking. Compared with persistently active participants, persistently inactive participants had a 4.0-fold higher job strain after adjustment for the confounders. Similarly, persistently inactive participants had a 2.7-fold higher job demands and a 1.8-fold lower job control. Decreasing physical activity was independently associated with high job strain (P < 0.01) and with low job control (P < 0.01).

Conclusions: Participation in regular LTPA during leisure may help young adults to cope with job strain. A long-term benefit of LTPA may play a role in the development of mental well-being.