women in sports, sports bras

Since a woman’s measured bra size differs significantly depending on whether she is breathing in or out at the time, respiratory state should be standardised during bra size measurements. The more accurate resultant bra fitting would reduce exercise-induced breast discomfort and related symptoms, according to Australian researchers.

A correct-fitting bra is imperative to good health, the researchers point out, with ill-fitting bras reported to contribute to numerous musculoskeletal problems in sportswomen, including neural symptoms in the arms, pain in the breasts, neck and back and exercise-induced breast discomfort.

With many different bra-sizing methods in use, it is not surprising that as many as seven out of 10 women – particularly those with large breasts – have been reported to wear the wrong size bra. The aim of this study was to look at the effects of respiratory state and measurement method on bra size calculation.

The bra sizes of 16 large-breasted (larger than C-cup) women were measured three times in two respiratory states: at the end of an in-breath and an out-breath.
The women’s chest (band) measurements were taken level with the ‘inframammary fold’ immediately behind the breasts. Cup size was measured in two ways:

• around the body to the most prominent part of the breasts with subjects standing and braless (the standard method);
• around the hemi-circumference of each breast, with subjects supine and braless.

The resulting bra sizes were then compared with those reported by the subjects.

Key findings were as follows:

• Chest measurements were significantly greater – by up to six inches – during inspiration than expiration;
• Band size calculated during both inspiration and expiration matched subject-reported size in only a minority of cases;
• While the standard bra sizing method rarely agreed with subject-reported bra size (to within one cup and band size of error), the breast hemi-circumference method did so in most cases.

The researchers suggest that respiratory state should be standardised during bra size measurement, with women reaching relaxed end expiration while chest circumference measurements are recorded.

Also a new valid and reliable bra sizing system, specifying posture, breast position and respiratory state, should be developed to help women select correctly fitting bras.

Br J Sports Med 2006; 40:970-974