Relationship between physical activity and general mental health

We investigated the relationship between physical activity and mental health and determined the optimal amount of physical activity associated with better mental health. Self-reported data from a national random sample of 7674 adult respondents collected during the 2008 U.S. Health Information National Trends 2007 Survey (HINTS) were analyzed in 2012. Mental health was plotted against the number of hours of physical activity per week using a fractional 2-degree polynomial function. Demographic and physical health factors related to poorer mental health were examined. The optimal range of physical activity associated with poorer mental health was examined by age, gender, and physical health. A curvilinear association was observed between physical activity and general mental health. The optimal threshold volume for mental health benefits was of 2.5 to 7.5 h of weekly physical activity. The associations varied by gender, age, and physical health status. Individuals who engaged in the optimal amount of physical activity were more likely to have reported better mental health (odds ratio = 1.39, p = 0.006). This study established a hyperbolic dose–response relationship between physical activity and general mental health, with an optimal range of 2.5 to 7.5 h of physical activity per week. ⺠General mental health was modeled against weekly hours of physical activity. ⺠The physical activity threshold for better mental health was 2.5–7.5 weekly hours. ⺠Higher and lower physical activity was associated with poorer mental health.