Why do your breasts jiggle when you run?

The primary reason breasts jiggle when a woman runs is due to the composition and structure of the breasts themselves. Breasts are primarily made up of glandular and fatty tissue, and they lack substantial internal support compared to other parts of the body with muscle and bone structure.

When a woman runs, the movement involves repeated up and down (vertical) oscillations. The breasts, being less supported internally, tend to follow the movement of the body, causing them to jiggle or bounce.

Additionally, the ligaments that provide some support to the breasts can stretch or relax over time, particularly with age, pregnancy, or significant weight fluctuations. This can further contribute to the jiggling motion of the breasts during physical activities like running.

However, it's worth noting that the degree of breast jiggle can vary among women and is influenced by factors such as breast size, breast tissue composition, and individual body structure. Some women may experience more noticeable jiggling than others during running, and some may not be affected to the same extent.

To minimize breast movement and discomfort during running, many women choose to wear supportive sports bras or exercise bras specially designed to provide adequate support and reduce jiggling.