Exercise has been shown to improve mood and reduce emotions of despair, anxiety, and stress.
It causes alterations in the areas of the brain that control stress and anxiety. It can also boost brain sensitivity to the antidepressant chemicals serotonin and norepinephrine.
Exercise can also stimulate the creation of endorphins, which are known to assist promote happy moods and lower pain perception.
Surprisingly, it makes no difference how hard you work out. Exercise appears to boost your mood regardless of the intensity of the physical activity.