Lead researcher Jeffrey J. VanWormer, PhD, of Marshfield Clinic Research Foundation, Marshfield, Wis., and his colleagues analyzed the relationship between stress levels, physical activity, and productivity in a sample of 2,823 Minnesota workers.
In general, higher stress levels were linked to greater productivity loss. Workers with higher body mass index were less productive, regardless of other factors.
After adjustment for body mass index, there was a significant interaction between physical activity and stress level.
For highly stressed workers, a high level of physical activity was linked to significant productivity loss. In contrast, for workers with relatively low stress levels, physical activity had less effect on productivity.
For example, for overweight employees who exercised seven hours per week, estimated productivity loss was eleven percent for workers who were highly stressed, compared to two percent for those with lower stress levels.
Worksite wellness programs that improve employee health generally lead to increased productivity. The study provides new insights into how stress affects productivity, particularly in combination with exercise and other lifestyle factors.
"This may indicate that some individuals essentially cope with high levels of stress by exercising more and working less," the researchers write.
The study appears in the October Journal of Occupational and Environmental Medicine.