Australian researchers recently completed a major review of 200 randomised trials on exercising to treat depression. It meant analysing over 14,000 people with clinical depression, which is characterised by at least two weeks of feeling low. After concluding exercise was an effective treatment, they went further and compared specific types of exercise with walking or jogging, yoga and strength training being about as effective as cognitive behavioural therapy and more effective than anti-depressant medication alone.

The review found yoga and qigong (a Chinese system of physical exercises and breathing control) are likely to be more effective for men, and strength training is best for women. Yoga is somewhat more effective for older adults and strength training can lead to greater improvements among younger patients. Dance is also great at lowering depressive symptoms.

The Australian guidelines suggest exercising three times a week for a minimum of nine weeks. But this new review found it didn’t matter how many minutes or sessions of exercise people did per week (as long as they did some). The effect of exercise was also the same whether you had mild or severe depression. However, the intensity of the activity does matter; so the more vigorous, the better. The benefits are also greater if you participate in exercise with other people as opposed to going at it alone.

Why is exercise good for depression? Experts believe there are a few reasons. When someone is depressed they can get stuck in a cycle of isolation — they withdraw socially and then find it hard to re-integrate — but exercising with others can break that cycle. Depression can also make you feel hopeless, making it difficult to get out of bed and do the things that are important to you. This can create a loop of guilt, but exercise can break this by providing a sense of accomplishment. There’s also a lot to be said for novel experiences. If you are learning something new, there’s a greater sense of satisfaction when you master it. On top of that, when we exercise we get a surge of neurotransmitters like dopamine which could be why more vigorous exercise has stronger effects.