Running is a popular exercise with few obstacles to participation and has been linked to improvements in cardiovascular, musculoskeletal, and mental health. Despite the many advantages of running, up to 72% of women report exercise-induced breast pain, which is a substantial barrier to exercise in general and running in particular.
Because breast tissue is passive, exercise-induced breast pain is mechanically caused by high tissue stresses and strain rates. High breast displacements and velocities prove these strain rates and magnitudes. External breast support in the form of a sports bra is frequently utilized to lower these tissue strains and strain rates in the passive female breast.
A recent study has shown that better running performance is linked to greater breast support. According to a recent study published in Frontiers in Sports and Active Living, greater breast support during running is related to stiffer knee joints, which changes the lower body biomechanics of female runners. Notably, a soft support bra was linked to a 2% increase and a high support bra to a 5% increase in knee joint stiffness. Overall, a well-made sports bra could boost a woman’s performance while jogging by 7%.
Dr. Douglas Powell and Hailey Fong, colleagues at the Breast Biomechanics Research Center at the University of Memphis, wanted to investigate further the effect of a good sports bra on running biomechanics.
“The biomechanics underlying improved running performance with greater breast support is poorly understood. Our study represents one of a series of research studies on breast support and whole body biomechanics,” explained Powell. “We wanted to identify strategies to reduce activity-induced breast pain for females, a group that makes up approximately 50% of the population.”
Scientists specifically observed the influence of breast support on knee joint stiffness during treadmill running. Twelve recreational runners in the age range of 18 to 35 who self-reported having a B, C, or D cup were fitted by a professional with one of two sports bras: a high-support bra.
The participants were instructed to conduct the experiment bare-chested in the control condition. The next step was for each participant to complete three three-minute running sessions in high, low, or bare/control breast support settings.
The scientists employed a 10-camera motion capture system and an instrumented treadmill to get the data. Individual retroreflective markers were placed on various regions of the participants’ bodies to track their movements. During the stance phase of jogging in each experimental condition, the scientists calculated knee joint excursions using Visual3D and knee joint stiffness and breast displacements using proprietary software.
The results of the trial demonstrated a correlation between increasing breast support levels and greater knee joint stiffness as a result of reduced common excursions. The knee joint stiffness was shown to increase by 2% and 5% in the low and high support situations, respectively, compared to the control condition. Overall, these findings and those of Powell and Fong’s earlier research suggest that a high-support sports bra can enhance a woman’s running efficiency by 7%.
Dr. Powell said, “The findings show that breast support not only influences the movement of the breasts but that compensations occur across the entire body. These compensations can lead to reduced running performance, increased injury risk, and even the development of chronic pain such as back and chest pain.”
Powell continued: “Over the past 50 years, limited evolution in bra design has occurred. Our findings, in conjunction with previous research studies, show that sports bras should be considered not only as apparel but also as sports equipment that can improve performance and reduce the risk of injury, playing a role in women’s health.”
- Douglas W. Powell, Hailey B. Fong, and Alexis K. Nelson. Increasing breast support is associated with altered knee joint stiffness and contributes to knee joint biomechanics during treadmill running. Frontiers in Sports and Active Living. DOI: 10.3389/fspor.2023.1113952