Experts suggest that women could be damaging their breasts by wearing the wrong type of bra and some women cause breast pain or discomfort by not buying the right-sized bra.
A breast biomechanics research team from the University of Portsmouth say women may be doing the damage without realising it as a result of ignorance or embarrassment.
They say these factors could be causing women to choose the wrong type of support leading to fragile ligaments becoming irreparably stretched.
The researchers from the university's Department of Sports Science have tested about 50 bra designs on hundreds of women during the past three years.
A New Zealand maker appealed to the Portsmouth team for advice on how to change their bra design so it could offer more protection during high impact sports.
The researchers tested the current design by measuring breast movement while the bra was being worn, and by asking women how they felt about the fit, shape, and design of the strap, underband, and other parts.
The research led by Dr. Joanna Scurr shows that breasts move up to 21cm (8.26 inches) during exercise and they move up and down, in and out and from side to side but most bras are designed to limit just vertical movement.
The researchers say many women prefer certain styles of bra and refuse to buy anything else and they found that with sports bras, many women will not buy a bra that resembles their everyday bra and does up at the back - they believe if it cannot be pulled over their heads it is not a real sports bra.
But many sports bras which are fastened at the back in the same way as a traditional bra, do an excellent job of supporting women's breasts.