When we exercise to lose weight, we usually do aerobic exercise or strength training to achieve the effect of reducing fat. It is fat, not weight, that is lost through exercise. So, the problem arises. 1/4 of female breast tissue structure is composed of fat. In the natural state, with the increase of age, the fat content in women's breasts can rise to 75%, and due to the effect of exercise to reduce fat, breasts will inevitably decrease.