Health experts have long known that exercise can help relieve depression, but what about people who aren’t depressed? Can exercise make them more happy or content? The short answer, from researchers at the University of Michigan, is yes. A U of Michigan news release reports that researchers at the school reviewed 23 studies on happiness and physical activity, including 15 observational studies and eight interventional studies. All of of the observational studies showed a positive direct or indirect association between happiness and exercise, while the eight interventional studies showed inconsistent results. And now the numbers: the researchers found that there was a threshold effect for the relationship of happiness and physical activity––happiness levels were the same whether people exercised 150-300 minutes a week, or more than 300 minutes a week. They also found that, in general, more exercise meant more happiness. Compared to inactive people, the odds ratio of being happy was 20, 29 and 52 percent higher for people who were insufficiently active, sufficiently active, or very active, respectively.