Degree Name

Doctor of Philosophy


School of Health Sciences


Background: Exercise-induced breast discomfort is a barrier to females participating in physical activity and has been associated with excessive vertical breast displacement. Sports bras have been designed to provide external breast support in order to minimise vertical breast displacement and, in turn, reduce exercise-induced breast discomfort. Adequate breast support during physical activity, however, requires both a supportive bra design as well as correct bra fit.

Research Question: The overall aim of this thesis was to systematically investigate factors affecting the fit and design of bras worn during physical activity in order to develop breast support strategies to minimise the exerciseinduced breast discomfort experienced by females when participating in physical activity. These strategies aimed to optimise bra fit and improve sports bra design through a greater understanding of breast biomechanics during physical activity.

Methods: A series of studies was conducted in two sections, bra fit (Section A) and bra design (Section B). The laboratory-based bra fit studies (Chapters 2-4) investigated the various methods used to determine bra size as well as the bra wearing behaviour and bra fit ability of females. A field-based clinical trial was then conducted to assess the effect of an educational intervention related to bra fit and design on the knowledge and bra wearing behaviour of females (Chapter5). The bra design studies (Chapters 6-8) used biomechanical methods to measure breast kinematics and kinetics during different forms of physical activity (treadmill running and deep water running) and in different types of breast support (fashion bra versus sport bra versus novel sports bra design).

Major Conclusions: Exercise-induced breast discomfort can be minimised by improving breast support through improvements in both bra fit and sports bra design. It is concluded that a revision of bra sizing guidelines and educating females in relation to professional bra fitting criteria are the main bra fit strategies to improve breast support and comfort during physical activity. For bra design, greater consideration of breast volume and breast shape, as well as the forces generated on the bra/breast spring, is recommended to offer improvements in breast support and comfort during physical activity. Specific bra cup design modifications, which can provide greater breast elevation and compression in encapsulation sports bras and increase the level of support relative to breast volume, are also suggested to improve breast support, in order to allow all females to exercise in comfort, irrespective of their breast size.