It is well known that physical activity can help reduce negative health conditions such as anxiety or depression, but what do we know about its effects on positive mental health? A new study by the University of Michigan shows that physical activity may result in increased levels of happiness.

The researchers, Weiyun Chen, associate professor of kinesiology at the University of Michigan, and Zhanjia Zhang, a doctoral student, set out to find out if physical activity is associated with happiness, and if so, what populations were most likely to benefit from it

By looking at health information on thousands of children, adolescents, adults, seniors, and cancer patients, the researchers found various results indicating an association between happiness and exercise.

The paper is published in the Journal of Happiness Studies.

The Study

The researchers began by reviewing existing studies from 12 countries on happiness and physical activity.

They did this by conducting a systematic search of databases, such as PubMed/Medline, PsychINFO, SPORTDiscus and Embase, to find original articles related to happiness and physical activity published after 1980.

They retrieved over 1,142 records and reviewed 23 studies in total. Fifteen of these studies were observational, while eight were interventional studies among various populations.

The researchers concluded that there was a positive association between physical activity and happiness in all 15 observational studies, but that the eight interventional studies showed inconclusive evidence.

Observational Studies

Overall, the researchers found that the odds of being happy were 20, 29, and 52 percent higher for people who were insufficiently active, sufficiently active, or very active, as compared to inactive people.

“The inactive means 0 to 9 minutes of moderate-to-vigorous-intensity physical activity (MVPA) per week, insufficiently active means 19 to 149 minutes of MVPA per week, sufficiently active means 150 to 299 minutes MVPA per week, and very active means 300 plus minutes of MVPA per week,” said Chen.

Young People

Many of the observational studies examined the relationship between physical activity and happiness in young people.

In one study, the researchers found that youth who engaged in physical activity just once a week, compared to those who did not, were 1.4 times more likely to be happy if they were normal weight and 1.5 times more likely to be happy if they were overweight.

Additionally, one study found that adolescents who were physically active at least twice a week were significantly happier than those who were active one or fewer times a week.

The researchers also found that college students who participated in physical activity were 1.3 times more likely to be happy than inactive students.

“Our findings suggest the physical activity frequency and volume are essential factors in the relationship between physical activity and happiness,” Chen said in a statement. “More importantly, even a small change of physical activity makes a difference in happiness.”

Adults

There were three observational studies on happiness and physical activity in adults.

In one study, exercise was associated with happier adults. In another study, happiness in adults was positively related to total minutes of exercise they had each week.

However, the findings also suggested that happiness in adults was mediated by their health and/or social functioning.

Special Populations

Three other observational studies involved special populations, including ovarian cancer survivors, people with cerebral palsy, and drug abusers.

Among ovarian cancer survivors, a significant association with happiness levels was found when patients met 150 minutes of moderate to vigorous physical activity.

While physical activity predicted happiness levels in children and adolescents with cerebral palsy, the researchers found only a slight association between happiness and exercise, no matter the intensity of the exercise, among drug abusers.

Interventional Studies

Physical activity in the interventional studies included aerobic, mixed school activity classes, and stretching and balance exercises for 30 to 75 minutes, ranging from one to five times a week for 7 weeks to a year.

While four of these studies showed a significant difference in change of happiness between the intervention group and the control group, three did not, resulting in inconclusive evidence.

Conclusion

Though the researchers were not able to draw the same conclusion from each of the population groups and studies, many of them indicated a link between physical activity and happiness.

“Based on the observational studies we reviewed, there was a consistently positive relationship between physical activity and happiness,” Chen said. “In other words, higher levels of physical activity were associated with higher levels of happiness.”