ABSTRACT
Investigations of the causes of depression have focused on biological factors, such as neurotransmitter deficiencies. In exercise depression research, depression is measured in two ways: by using standard classification criteria and determining, through a clinician-administered interview, whether the individual satisfies these criteria and by using self-report measures. More severe depression might take the form of an unexplainably depressed mood. In many exercise studies, the depression score obtained on the questionnaire of choice is examined before and after a single bout of exercise or, more commonly, before and after some type of exercise training program lasting several weeks or months. An increasing number of cross-sectional epidemiological studies have examined the role of exercise in promoting and maintaining mental health. The depression reduction occurred for both acute and chronic exercise; in other words, depression was reduced following single bouts of exercise and following longer-term programs of physical activity.
