Physical activity, psychological complaints, and occupational health

Occupational health professionals and researchers are primarily concerned with examining and preventing the specific health effects of exposures to chemical and physical agents that are unique to the work environment. When looking beyond work related diseases to other diseases and broader health outcomes such as disability, absenteeism, and general health status, we must also consider the effects of factors outside of work, and the interaction of these factors with work exposures. The article by Bernaards and colleagues¹ provides further evidence of the importance of taking a broader view of worker health and safety.

The study by Bernaards and colleagues used data from the Dutch SMASH study (Study on Musculoskeletal disorders, Absenteeism, Stress, and Health), a three year prospective cohort study of over 1700 Dutch workers. Baseline and annual questionnaire data on strenuous leisure time physical activity were used to predict four health outcomes: depression, emotional exhaustion, perceived general health status, and work absenteeism due to psychological complaints. The study found that strenuous leisure time physical activity was associated with a lower risk of depression, emotional exhaustion, and poor general health, as well as with a lower risk of work absenteeism due to psychological complaints. The beneficial effects of exercise were strongest in persons with sedentary jobs. These results join those of a few other longitudinal studies showing that higher levels of leisure time physical activity are associated with lower risks of future depression and depressive symptoms.^2,3

Surprisingly, this study found that strenuous physical activity at a frequency of once or twice a week was associated with lower risks of depression than exercise at three or more times per week. Unfortunately, the relatively small number of workers in the highest category of exercise frequency meant that …