Physically fit people are less vulnerable to depression. Regular activity can also markedly reduce symptoms of depression for many people. Exercise affects mood in four ways.

First, it can produce a brief runner’s high just after exercising in some people. Second, after a few weeks of regular activity, a general improvement in mood tends to begin. Third, improvements in physical fitness are associated with improved energy, which can enable you to do more. Finally, exercise can be a good way of burning off stress when you are feeling tense.

How to Get Started

Pick the right activities. The biggest challenge is keeping at it. Pick activities that you really enjoy. Both aerobic (cardiovascular) exercise (in which your heart rate accelerates into a target range for 20 minutes or more) and anaerobic exercise (such as weight training or yoga) have shown positive effects on mood. Select the type that suits you best. Variety also helps: pick more than one activity and alternate them.

Stretch and warm up first. Learn how to do stretching exercises properly, then make sure to do them before each exercise session. This can help reduce the likelihood of exercise-related pain or injury.

Frequency is more important than duration. Regular short periods (three to four times a week) are better than irregular long periods.

Focus on enjoyment. People who exercise for enjoyment and challenge seem to show bigger mood improvements than people who exercise mainly to look better. Try to put an emphasis on how you will feel rather than how you want to look.

The effect of exercise on bipolar (manic-depressive) mood problems is less clear than for other forms of depression. Strenuous exercise during a manic episode or upswing in mood may aggravate the problem in some cases. Gentler exercise at these times may be preferable.

Nothing changes overnight. Use goal-setting when developing a fitness program, and be sure to pick something achievable. For example, aim to swim once for five minutes rather than starting off by committing yourself to a daily 70 laps.