If I come home in a bad mood, my husband usually suggests I head out for a run or over to the pool for a swim. That’s because he knows that exercise helps to improve my frame of mind. But does it also help improve the symptoms for people suffering from clinical depression?

A new systematic review tackles this topic. The review, published in the Cochrane Database, included 37 clinical trials with a total of more than 2,000 participants that compared exercise to either no treatment or another clinical intervention.

The researchers found that exercise is moderately more effective than no treatment for reducing symptoms of depression, but that the methods used in the studies were not always robust. When compared to psychological or pharmacological therapies, they found exercise to be approximately as effective, but not more effective.

The reviewers concluded that more research is needed to investigate the details of what types of exercise could most benefit people with depression, and the frequency and duration needed to make a difference. They also suggested more large clinical trials that compare exercise with antidepressants or other psychological treatments.

The take-home message: Exercise does improve depressive symptoms, although it’s not clear how much is needed to make a difference. Considering exercise’s other benefits — including weight control, cardiovascular health, and muscle and bone strength — it’s clearly a worthwhile endeavor.