Aspects herein provide for a support garment having a vibration damping structure that is positioned between the breast contacting surfaces of the support garment. The vibration damping structure has a shape and/or material characteristics that enable it to substantially fill the space defined by a medial aspect of the wearer's breasts and the wearer's sternum. This positioning and placement facilitate the damping structure's ability to absorb and dissipate impact forces generated at least through the medial-to-lateral movement of the wearer's breasts during, for example, athletic activities.