For 10 years, bra maker Berlei has worked with the Australian Institute of Sport's biomechanics unit, measuring breast movement and examining how varying bra designs can minimise breast bounce.
The research revealed that an unsupported 12B bust can bounce up to 8cm and a 16DD bust as much as 19cm during high-impact exercise such as running. It also found that during various exercise drills, breasts do not just move up and down, but also sideways and in directions independent of each another.
Reducing bounce minimises damage to the soft tissue, known as Cooper's ligaments, which give breasts shape. The AIS found that more than two-thirds of Australian women risked permanent damage by wearing ill-fitting bras while exercising or the wrong sort of bras entirely.
It is also recommended that women replace their sports bra at least every six months, depending on how often the bra. Only Berlei Sports bras are tested, used and approved by the Australian Institute of Sport (AIS).