What Is the Effect of Breast Size on Running Economy and Upper Body Biomechanical Factors Contributing to Running Economy?

Women with large breast volumes experience significantly more breast motion compared with their smaller breasted counterparts during running, despite the presence of a high-support sports bra. Although increased breast motion as a result of breast size did not translate to differences in running economy, it did alter upper body biomechanical factors known to influence running economy-total body center of mass vertical excursion and peak angular velocity of the trunk in the frontal plane. Future research should explore what effect excessive trunk motion has on the mechanics of the lower limb during running among women across the breast size spectrum, as well as how this may influence neuromuscular control and coordination between the upper and the lower limb during running.