A new study looks at the connection between breast size and exercise habits, and many women can totally relate to the findings.

By Lauren Phillips
Updated March 08, 2019

Bra sizes can impact how you dress, what kinds of bags you carry, and even how you walk—and, according to a new study, your breast size can even affect your exercise habits. Any well-endowed woman (or any woman with particularly sensitive breasts) can tell you that running without a sports bra is just asking for trouble, but now there’s scientific support acknowledging that exercise can be challenging for large-breasted women.

The study, as reported by the New York Times, was published in the Journal of Science and Medicine in Sport in March and surveyed 355 women on their exercise habits and whether the women thought their breast size influenced how they exercised. The authors of the study—researchers at the Biomechanics Research Laboratory at the University of Wollongong in Australia—also took precise measurements and scans to classify each participant’s breasts as small, medium, large, or very large. (Because we all know bra size can be notoriously inconsistent.)

The results showed that, as breast size increased, participation in physical activity (especially vigorous physical activity) dropped. Very few of the women classified as very-large-breasted reported jogging recently, and many women with larger breasts said they thought their cup size prevented them from exercising easily. Across age and body mass index, the results were consistent: Woman of all body sizes with larger breasts exercised less than women with smaller breasts.

Depending on the activity, any woman’s breasts can move during exercise, and sports bras can’t completely stop that movement, even for small-chested women. Women with larger breasts, then, can experience a lot of breast motion during exercise even when they wear a sports bra. Because that motion can cause varying degrees of pain and soreness during and even after exercise, it’s no surprise that many women with large breasts avoid high-impact workouts.

Now there’s scientific evidence to back up your claim that running hurts too much, but exercise is still a very important part of any healthy lifestyle. Avoiding all exercise for fear of causing breast pain can mean you’re missing out on so many different health benefits, including increased bone strength and decreased stress.

Instead of cutting out exercise completely, look for low-impact activities (such as this exercise ball workout) and be sure your sports bra is supportive and well-fitted. Wearing two sports bras can help even more, if you’re determined to do a vigorous workout and really want to ward off any potential breast pain. And if breast-related soreness post-exercise is really too much, you can try water-based exercises such as swimming and water aerobics for even more support.