According to one U.S study which is published in the Archives of Physical Medicine and Rehabilitation, any kind of exercise can better enhance the mood of a person. The study focused on middle-aged non-exercisers rather than the young and fit people. Factor that affects the exercisers to maintain a regular exercise program is the lack of an increase in exercise-induced vigour or related mood enhancements, said Martin Hoffman of the University of California — the lead author of the study. Hoffman analyzed pre and post exercise responses to mood-related questions among non-exercisers, regular exercisers and marathon runners. Hoffman found that those who do aerobic exercise had an increase in vigor and decrease in fatigue among marathon runners and regular exercisers but not among non-exercisers.