You know sports bras stink, and now there’s science to support it.

A new study from the University of Portsmouth shows that breast movement negatively impact running form, and the poorly designed sports bras on the market aren’t doing their job.

By placing reflective markers on subjects’ breasts and tracing the movement with infrared cameras, researchers found that during running women’s breasts don’t just move up and down, they “arc” through a complex figure-8 pattern.

No sports bras are designed to handle this lateral movement, working either by encapsulation (cupping) or compression (smashing against the chest). The resulting discomfort can discourage women, especially those with larger bosoms, from exercising.

Australian scientists, after noticing how large-breasted women wearing crop-top sports bras running in water felt little breast discomfort, came up with a new experimental design that combines foam pads with compression to mimic the supportive buoyancy the water provided.

The result was a bra that prevented both horizontal and vertical breast movement. Women, particularly those with larger breasts, gave it higher comfort ratings by a huge margin.

Until manufactuers come around or people start making them on Etsy, the best bet women have is to:

Find a sports bra that “feels supportive,” Ms. White said. That advice may “sound obvious,” she added, “but many bras are marketed as a sports bra” but are instead “just a fashionable crop top that has very stretchy material and that would not provide a lot of support.” To test support, jump “up and down in the changing room and assess how much movement occurs.” The chest band should be “firmer than an everyday bra, but should not dig into your skin.” All in all, if the bra “is uncomfortable, then this is probably not the bra for you.”

Research Shows The Ideal Sports Bra Has Not Been Invented [NYT] (Thanks to c-side!)

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