Abstract: The menopause is characterized by the progressive decrease in estrogenic secretion and associated with bio-psycho and social changes which in turn impairs quality of life. This experiment was conducted to determine if exercise training has a protective role against the deleterious effects of aging in ovariectomized rats. Control rats and ovariectomized rats 12 weeks after surgery were subjected to a 4 weeks treadmill-running program. Subgroups established were young animals, old animals, ovariectomized animals, young exercise-trained animals, old exercise-trained animals and ovariectomized exercise-trained animals. In exercise groups, rats were subjected to treadmill exercise during which time each rat walked on a motor-driven treadmill at 15 m min^-1 speed and 15° incline once every 2 days during 10 days for three courses as 5, 10 and 15 min day^-1 totally for 30 days. In ovariectomized rat, heart tissue was remarkably dens fibrosis and an increase in necrotic cell density, possibly resulting from myocyte defect. Findings of old exercise-trained animal group more resembled young animal group rather than ovariectomized animal group and ovariectomized exercise-trained animal group.