Combined Effects of Bra and Shoe Support on Impact Accelerations and Comfort in Female Runners

Abstract

Sports bra design plays a critical role in running, as breast discomfort often hinders exercise participation for many women. While breast movement has been analyzed across support levels, most studies focus on discrete time-domain variables (peak acceleration). However, impact frequency content and tissue vibrations are also key factors the body may regulate to maintain comfort and performance during running. This study explored how different sports bras and running shoes affect breast and foot-strike impact forces and comfort in female runners. Thirty-four women ran in four conditions that combined high and low support bras with high and low cushion shoes. Impact accelerations at the ankle and breast, breast-body time lag, and PSD in two frequency ranges at the ankle and breast were measured using wearable sensors, and participants rated sports bra and shoe comfort. Results showed that shoes with more cushioning reduced impact forces at the ankle and were rated as more comfortable. Sports bras with higher support significantly reduced breast movement and better managed impacts at medium and high frequencies, which could be linked to discomfort. There were no meaningful changes in breast movement caused by the shoes alone, but there may be subtle interactions worth further investigation. These findings are important to understand the interactive effect of sports bra and shoe support, and how sufficient upper body support may enable female runners to tolerate or absorb greater impact variability at the foot-strike level. Overall, both sports bras and running shoes play important roles in managing impact and comfort during running, highlighting the need for female-specific design considerations in athletic gear.