As you probably know, when it comes to medical research, women are under-represented. The most famous example was the lack of female crash test dummies, but studies on issues like heart disease and cancer have also mainly focused on male participants. Enter Lululemon. The popular yet pricey athleisure line funded a study to research breathing patterns in “elite” female runners. The tests were conducted on treadmills, with the participants doing different treadmill workouts while wearing custom sports bras that were adjusted to different levels of tightness around their rib cages. Surprise! The study found that wearing a sports bra that’s too tight around your rib cage may “compromise” a woman’s ability to breathe properly while exercising, which can also affect their running performance. Lululemon really dropped all that money to tell us something every single woman who’s ever worn a sports bra while exercising could have told them for free.

Be cautious: It turns out that wearing a tight sports bra while exercising may not be good for your health, according to a new study. The study, which was published in the National Library of Medicine, was funded by Lululemon Athletica and conducted by the University of British Columbia. During their research, they examined the breathing patterns of nine elite runners.

While on a treadmill, runners wore custom sports bras that could be adjusted to different tightness levels. The bras were designed for individuals with rib cage sizes ranging from 30 to 34 and cup sizes of B or C. Throughout the study, the runners engaged in various treadmill workouts, during which they adjusted the tightness of their sports bras differently for each session.

The study — which focused on the tightness only around the rib cage — revealed that women who wore a sports bra that was too tight took fewer breaths and exhibited a higher breaths-per-minute rate, noting that “respiratory function may become compromised by the pressure exerted by the underband.”

However, those who wore a less constrictive sports bra “resulted in a decreased work of breathing,” and improved one’s running economy by decreasing submaximal oxygen uptake.

“People ask, ‘What sports bra should I wear?’ I say, ‘Wear one that is correctly fitted,’” Shalaya Kipp, the lead author of the study who is now a postdoctoral fellow at the Mayo Clinic in Minnesota, told the Washington Post. “That’s probably the biggest thing that would help.”

Specifically, the study showed how wearing a looser bra had a 1.3% improvement rate for a person’s running economy. Kipp told the outlet that a 2% increase in running economy would help a three-hour marathon runner improve their time by three minutes.

“It was quite invasive,” Kipp, who also competed in the 2012 Olympics and participated in the study, said. “It’s the hardest experimental protocol I’ve ever had someone do.”

“A decline in lung function makes breathing harder, which is especially critical during exercise or daily physical activity,” she added, per the outlet.

[From People]

I think most of these results are common sense. Of course wearing a too-tight sports bra is going to make it more difficult to breathe while running. Wearing anything too tight from your hips through your shoulders is going to make it difficult to breathe! I think the problem most women run into when buying a sports bra is wanting to feel that extra support to avoid bouncy boobs. Running when you’re flopping around is equally as painful and annoying. So, just like with everything else made for women, the struggle is real. Also, I wonder if Lululemon sponsored this “study” as a way to promote whatever wildly overpriced custom sports bras they want to sell to women with cup sizes C or less. Be the heroes, Lululemon! Give us a supportive yet comfortable sports bra for under $50!

On a more serious note, I do want to take a minute to do a quick PSA on the topic of too-tight sports bras. Obviously, this will not be the case for most women, but if your sports bra suddenly feels too tight without reason, please consider getting checked out by your doctor. My friend is a marathon runner. She had a routine mammogram last winter and it was clear. This past fall, while training, she noticed her sports bra felt too tight and that she was having trouble breathing. It kept happening, so her doctor sent her for another mammogram and she ended up being diagnosed with Stage IV triple negative breast cancer. I don’t want to be a downer or scare anyone! But, it’s been weighing on me, so I thought it was important to mention it just in case it could help any of you out there.

Photos credit: Andrea Piacquadio, Andres Ayrton, The Lazy Artist Gallery and Monstera Production on Pexels