Breast reduction exercises do not actually reduce breast size, but tend to tighten the muscles of the chest; breast reduction exercises therefore create the impression that the breasts are being lifted. In addition, doing breast reduction exercises often changes the shape of the breast. The changes brought about by such breast reduction exercises as arm circles can vary from person to person.

The specific effects of various breast reduction exercises are related to the proportion of glandular and fatty tissues to muscle tissue. Most breast reduction exercises tone the muscle tissue that lies under the glandular and fatty tissue, although some breast reduction exercises also help reduce the amount of fatty tissue in the breast. Increased muscle tone from breast reduction exercises results in a flatter appearance in the chest, but the changes are often minimal. Breast reduction exercises that reduce fat tissue can further shrink the breast, but there appear to be no breast reduction exercises that decrease glandular tissue. Most large breasts are comprised mainly of glandular tissue, so breast reduction exercises make only moderate changes to breast size.