March 6, 2013 at 10:14 AM ET
By Scott Douglas, Runner’s World
You're probably familiar with the post-workout feeling that, for the next little while, all is well with the world. That exercise-induced glow can wear off pretty quickly, of course, but does that mean that any happiness imparted by being inactivity is temporary and fleeting? No, according to a study published in the American Journal of Epidemiology, which found that regular activity is linked with greater happiness over periods of years.
This Canadian study analyzed data from eight National Population Health Survey cycles, spanning 15 years, to see how activity level at the beginning of the survey and then years later was associated with happiness. In its design, it attempted to get around that, in the short term, exercise might be linked with greater happiness because happier people might be more likely to exercise. The researchers looked at data on activity and happiness that was collected every two years.
Respondents to the survey were asked about participation in several kinds of leisure-time physical activity and were divided into active and inactive groups based on their daily energy expenditure. They were also asked to characterize how happy they were, and were divided into happy and unhappy groups based on those replies. People who were unhappy when first surveyed were excluded from the study.
The researchers found that being physically active was associated with 85 percent higher odds of being happy at the start of the study. Among happy people, those who reported being inactive at the beginning of the survey were 49% and 45% more likely to be unhappy two and four years later than people who reported being active. Happy people who were inactive in two consecutive cycles were twice as likely to be unhappy two years later than people who were active at both times. People who changed from being inactive to active were more likely to report feeling happy two and four years later.
These finding suggest that changes in activity level affects changes in mood over long periods of time. Today's run is likely helping your mind not just today.