Petra Zeiler(Photo)
Anyone with breasts will tell you that sports bras aren’t totally comfortable. (Petra Zeiler)

We’re in the Middle of a Sports-Bra Revolution

Technological advances and a growing line of research have paved the way for a new class of support systems that are comfortable, look good, and fit a wide(r) variety of bodies.

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I’ve only known Helen Kenworthy for an hour when she asks me to take off my shirt. We’re in a small room with a mirror at the headquarters of Brooks Running in Seattle. Down the hall is the shoe and apparel brand’s sports-bra design department, where well-lit work tables are piled with fabric cutouts, spools of zipper, and honeydew-size plastic molds marked A cup, B cup, and so on.

Kenworthy, a senior bra developer for Brooks, wraps a measuring tape around my bust, then my rib cage, and tells me matter-of-factly that I have been wearing the wrong size bra my entire life.

It’s not my fault. I—and, in fact, most women—don’t have the necessary information to shop correctly. Over the course of a month or even a day, Kenworthy explains, women’s chests can fluctuate by as much as a full cup or band measurement. Add in the fact that women’s breasts have unique compositions, each requiring slightly different forms of support, and you get a complex fit matrix that has to do with much more than a number and a letter. Sports bras are only just catching up to those realities.

“We’re retraining ourselves on how to develop, understand, and speak about fit preferences versus size,” she says. In other words, for Brooks and many other companies, the days of designing bras for support at the expense of comfort and then telling women to buy all their sports bras in one true size—even if that means they’re painfully tight—are over.

It’s more than a shift in mindset and sales tactics. I’d come to Seattle to get an up-close look at Dare, a collection of six sports bras that launched in February and includes a crossback, a racerback, a scoop-back, a high-neck, a zip-front, and a strappy model, all of which run from a 30A to a 40F. The new models look nothing like the sports bras that have defined its women’s line for decades.

Standby classics like the Juno, the Rebound Racer, and the Maia have distinctive features like Velcro shoulder straps, chunky back clasps, and contoured full-coverage cups. I had a strained relationship with those bras growing up. They were the only ones that worked for my 32D chest, but their bulky design made me feel ashamed of this part of my body, apparently so outsize that it required metal and Velcro or fabric up to my collarbones just to stay put.

The Dare styles retain that contoured shape, but everything else about them is entirely modern: laser-cut seamless edges, cups that are heat-molded to offer encapsulation—cupping each breast separately like your regular lingerie bra—without the need for underwire or extra stitching. They look good. And, as Kenworthy explains, they’re also far more comfortable without sacrificing support.

Brooks isn’t alone. Brands like Lululemon, Nike, and Reebok have all begun to revamp their offerings. For the first time, companies are investing in research and development to understand how breasts really move and how women want their sports bras to feel.

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Anyone with breasts will tell you that sports bras aren’t totally comfortable. This is something Outside has reported on numerous times over the years. For some, the problem is chafing. For others, it’s compression that’s so overkill, it hurts or restricts your ability to breathe. Still others have trouble finding options that fit both their chest and their rib cage without being too tight or loose in one place or another. Then there’s the issue of getting them on and off, which can often feel like yet another strenuous part of a workout.

In January 2019, 632 women responded to an Outside reader survey about sports bras. Of those women, who ranged in size from AA to I cups and 32 to 48 bands, 61 percent said they were unhappy with the high-impact sports bras available to them (40 percent said the same of low-impact options). The most common refrains: discomfort and a lack of aesthetics.

People without boobs might find this surprising, since the whole point of a sports bra is to make breasts feel less painful during activity. But it all starts to make sense when you consider that the modern-day sports bra was initially designed with the exclusive goal of minimizing breast movement. 

In 1977, Lisa Lindahl, Polly Smith, and Hinda Miller brought the Jogbra to the world. The garment—which was originally two jockstraps sewn together—used compression to pull breasts close to the chest so they’d move less during sports like running. “It was not attractive at all,” says Lindahl. “But I didn’t care! And the women who were buying it didn’t care. The point was that, all of a sudden, I wasn’t having to pull up my bra straps, and I wasn’t getting horrible comments when I ran down the street.”

Other women felt the same way—and not just runners. Within a decade, the Jogbra company had expanded its line to include a bra designed for women with smaller chests and those who did sports that involved less jumping and jiggling, like hiking. Then came a Jogbra for large-chested women that supported via encapsulation as opposed to only compression.

The company defined each bra by how much or how little it did for breast movement, using something called the Motion Control Requirements Chart. The company’s founders also coined three new terms: low impact, medium impact, and high impact. A low-impact bra was for activities like walking, while a high-impact bra was for sports like running or tennis. Whether a bra was low impact or high impact also depended on the size of your breasts.

(Lisa Lindahl)

As sports bras took off in popularity and more companies started making them, that singular focus on motion control stuck—especially for high-impact bras and those for big chests. This was largely because breasts are a uniquely difficult body part to design for. They’re essentially sacks of fat and connective tissue that move independently from the rest of the body, with no muscle or bone to halt motion. “It’s passive tissue that’s on the body,” says Chantelle Murnaghan, director of Whitespace, Lululemon’s in-house product-testing lab. “It presents a really great engineering problem.” So sports-bra designers focused on controlling this most unruly body part—often at the expense of user experience. This usually involved adding more layers or hardware like underwire, says Barbara Ebersberger, vice president of apparel at Reebok. “This made the bra heavier and more uncomfortable,” she says.

Most designers thought of discomfort as a natural side effect of wearing your sports bra correctly. “We would try to figure out how to put another feature in there, another layer of stabilizer to make it more supportive,” says Julianne Ruckman, Brooks’s senior product-line manager for women’s apparel. And when it came to matching customers with the right size, “we used to fit bras by cranking [the measuring tape] as tight as possible without breaking a rib.”

Of course, sports bras are also tied up in the fraught cultural symbolism that surrounds women’s bodies. “Historically, women’s breasts were seen as a sign of inferiority, as yet another reason why [women] were ill-suited for sport,” says Jaime Schultz, professor of kinesiology at the University of Pennsylvania. “There was an article at the turn of the [19th] century in The New York Times about why women made lousy swimmers. One of the reasons, the author argued, was because they have breasts where men have pectoral muscles.” In 1995, the Associated Press reported that golf commentator Ben Wright said that “women are handicapped by having boobs” because breasts get in the way of their swing. Breasts—and, thus, sports bras—are also a sign of sexuality. The result is a whole lot of shame (whether your breasts are too small or too big) wrapped into a relatively small piece of clothing. It’s no wonder that many women look to sports bras as a means of strapping down their chests as tightly as possible.

To be clear, there have been comfortable sports bras out there for a long time. Most of them—at least until recently—just weren’t high impact. “There was this paradigm that existed,” says Lululemon’s Murnaghan. “You could have a bra that performed extremely well but was very rigid and uncomfortable, or you could have a bra that was very comfortable but then you sacrificed performance.”

(Courtesy Brooks)

Recently, things have begun to improve. In 2017, when Outside reported on the sorry state of the sports-bra industry, companies were talking about new technologies, fabrics, and manufacturing techniques that would change the game. Within months of that story, the technologies began to show up in actual products.

First Lululemon launched the Enlite bra, becoming one of the initial major athletic brands to break the comfort-versus-support paradigm. The bra debuted in 20 sizes, from 32 to 38 bands and up to an E cup. Despite featuring four straps, a back clasp, and maximum coverage—and the support that comes with all of that—the Enlite is sleek and unobtrusive. Perhaps most notably, it maintains the wearer’s natural curves rather than smashing them down like most high-impact bras. This is thanks largely to a nylon-Lycra-blend fabric that is lightweight and stretchy yet has the heft of something thicker and is heat moldable, which translates to a higher degree of support and bounce reduction without the need for overbuilt construction. The bra earned rave reviews on the internet from women who wear C, D, and DD cups.

That same year, Nike launched the Fe/Nom Flyknit, a pullover racerback constructed with 3-D-knit technology that the brand originally developed for running shoes. The Fe/Nom is constructed from two single-layer panels into one piece by machines that can vary the thickness and stretchiness of the material as they go. This means it’s virtually seam-free and has compression only where needed, allowing the chest to move and breathe with less restriction.

In 2018, Reebok launched the PureMove racerback, which uses sheer thickening fluid (STF), a chemical application originally used by the military and NASA that is pliant at rest but stiffens under impact. The PureMove becomes highly supportive (though still moderately flexible) for activities like running but softens so it’s less constrictive when the wearer is just standing around or running errands.

When it came time to design its Dare bras, Brooks had to retrain its designers, says Ruckman. In a notable in-house experiment, Brooks gave money to a handful of employees to buy whatever running bra they wanted from any brand, then conducted tests with these bras followed by a Brooks bra. Overwhelmingly, the bras that employees chose were less supportive than the Brooks styles, but the women liked them more. The company learned that some women “actually prefer to run in a style that is less supportive,” says Ruckman. For many of Brooks’s sports-bra designers, this was a revelation. “Their education tells them to say, ‘I can do that more supportively,’” she says. “And I said, ‘But how can you do that more comfortably?’”

Most of Brooks’s classic high-impact bras reduce between 65 to 75 percent of breast motion. In building the Dare line, Ruckman told designers to stay within 50 to 70 percent of motion reduction. That range hits a sweet spot that’s supportive enough to handle the uncomfortable, annoying, and physically damaging side effects of breast motion without going overboard to the point of discomfort. Anything much higher, she says, is “doing a disservice to the runner.”

Dialing back support also allowed designers to eliminate excess features. Strips of fabric reinforcement around the underarm, formerly a fixture on many Brooks standbys, are gone on the Dare bras, replaced by clean, seamless, laser-cut edges that reduce chafing and improve comfort by allowing the bra to flex instead of dig in. Low-profile metal shoulder-strap sliders, like the ones on traditional lingerie bras, are replacing the old Velcro adjustors. The cups are all heat-molded—a manufacturing technique that bonds multiple fabrics together without sewing—into shapes that mimic the body’s natural curves.

Paradigm shifts and better manufacturing alone aren’t responsible for today’s modern sports bra, though. Growing research about breasts is fueling the change. “Breasts and bras were always quite a taboo subject, whereas now I think cultural changes have occurred, and they are spoken about more openly,” says Brogan Horler, head of product testing at the University of Portsmouth’s research group in breast health. Horler’s team at the university is a world leader in breast biomechanics research and consults with many top sports-bra makers globally, including Brooks. Another group, at the University of Wollongong in Australia, now also specializes in studying how to minimize breast pain through bras.

Thanks to research from organizations like these, as well as extensive lab studies done internally by sports-bra makers, we know that the majority of support comes from a bra’s band, not the straps, and that breasts don’t just move up and down. “They move up and down, side to side, and in and out,” says Lululemon’s Murnaghan. “It’s the acceleration, or how fast the breast is moving through that motion, that is most critical to create a solution around.”

Companies are also finally taking advantage of information we’ve had for decades. For example: not all breasts need the same kind of support. Some breasts have more fatty tissue, while others are primarily made up of connective and glandular tissue. (The former is squishier, while the latter is denser.) How these different compositions impact the way a breast moves is the subject of ongoing research. “We do not yet know what impact different breast compositions have on breast biomechanics,” says Jenny Burbage, a biomechanics expert with the Portsmouth breast-health research group. The team she works on is researching the subject.

One thing has become clear: your breast composition probably impacts the kind of sports bra that you’ll find most comfortable. According to Ruckman, someone with more fibrous tissue is likely to appreciate an encapsulation-style bra that lifts and separates the breasts. “That breast tissue is not moldable,” says Ruckman. “It’s harder, denser. If you try to smash that down, that’s uncomfortable. You want to lift and complement it by putting a shell over it.” Meanwhile, women with fattier breasts are likely to prefer compression-style bras. That’s because fat is pliant—more squishable—and also jiggles more. “[Those kinds of women] want compression,” says Ruckman. “If you try to lift a fattier tissue, there will still be motion. If you compress it, it stops that motion.” (The only way to tell your breast composition is through an MRI, though many women can probably intuit where they fall just based on the kinds of bras they gravitate toward—and the kind they hate.)

For Brooks, the solution to this is creating bras for different kinds of breasts. The Dare collection is comprised of all encapsulation-led bras. Next up, for 2021, will be the Drive collection of compression-led bras.

For the first time, companies are investing in research and development to understand how breasts really move and how women want their sports bras to feel.
Mixed race woman working out in gym
(Peathegee Inc/Getty)

Of course, there are still a number of crucial areas for improvement. First, price: top-end sports bras run anywhere from $60 to nearly $100. Second, the sizing range. Many brands are making bigger bras. Lululemon’s line goes up to a 38DD and offers some of its popular low- and medium-impact bras in a C/D-specific version. Both Brooks and Nike have styles specific to D and E cups.

But Nike’s Fe/Nom Flyknit, arguably one of the brand’s most supportive and high-tech bras, only goes up to XL, which is the equivalent of a 40C or 38E (small, medium, and large sizes often cover multiple cup and band sizes). The PureMove bra tops out at XL, which is equivalent to a 42D. Next month, Reebok is set to launch the updated PureMove +, which will accommodate up to F cups.

There’s also a lack of good-looking low- and medium-impact bras for large chests. “In our DD/E-plus focus groups, we would bring out styles that were strappy, and there was a consensus among the women that they didn’t feel like they could find styles that had those [qualities],” says Ruckman. “They didn’t feel sexy in their sports bra. And they wanted that.” The sleek, seam-free Dare bras, and others like the Enlite, are designed to fill that desire for stylish, big-boob-friendly bras.

But in the low-impact category, many women are still missing out. Brooks’s Dare Strappy Bra is designated for A/B cups. “Given how many sizes most of our new styles are built for, we wanted to ensure that one style was really targeted at the insights we heard specifically from the A/B wearer,” says Ruckman. “Predominantly, they wanted less front-neckline coverage, little to no hardware, and an aesthetic that worked with a racerback top.” She says that simply making the Strappy Bra in a larger cup size won’t yield the motion reduction necessary for a running bra.

For now, one of the only major companies making low- and medium-impact plus-size bras for women above a D cup is Nike, which offers two styles. Reebok offers two low-impact and one medium-impact plus-size bras, and Target offers seven medium-impact plus-size bras.

Thanks to the athleisure trend, more women than ever are wearing sports bras not just for working out but for all-day wear and even as fashion accessories. “It is changing the consumer mindset of what comfort means,” says Ruckman. Those demands are pushing the innovation for bras, and they’re also causing technology to trickle down from luxury, high-end athletic brands to affordable, everyday ones, like Target. The big-box store offers dozens of sports bras, including plus-size options, through its C9 Champion and Joylab lines. Many of these bras feature some of the same modern technologies as their name-brand counterparts, like molded cups and laser-cut edges and perforations. All are under $30, and many are under $20.

Then there are the small companies launching bras of their own to solve problems few big brands are taking on. Molly T, founded in 2019, makes a wrap-style bra with Velcro under both armpits so the wearer can adjust her level of support as she transitions between running, yoga, and everyday wear and as her breasts change size.

Têra Kaia (formerly Arêt) is a company founded by three women—swimmers and a climber—who struggled to find bras that would accommodate their back muscles. Their flagship Toura bra, which comes in A-C and C-DD versions, is designed to pull double duty as a sports bra and swim top. It uses a contoured, elasticated bottom edge that hugs the rib cage and supports breasts without digging in like traditional straight-cut bottom bands.

Thanks to the athleisure trend, more women than ever are wearing sports bras not just for working out but for all-day wear and even as fashion accessories.
Beautiful girl belaying during a rock climbing trip in Kalymnos, Greece.

Ultimately, though, all these technological innovations, paradigm shifts, and design changes are moot if women don’t alter the way they shop for bras. The vast variety in chest shapes and breast-tissue compositions mean that bras fit women differently—even women of the same size. Simply ordering bras online in the same size you’ve always bought won’t do.

This year Lululemon is planning to equip a few of its stores with a bra-fit program that involves running on a treadmill wearing a sensor-equipped bra that “uses intelligent digital technology to map guests’ unique physical requirements, personal-movement profile, and sensory preferences,” says Murnaghan. The idea is to match women with their perfect sports bra.

Brooks is taking a different tack. It wants the in-store buying experience to “be less medical and more preference-based,” says Ruckman. Through its retailer fit-training program, the brand is beginning the process of teaching shop employees to ask women trigger questions—How old are your lingerie bras, and what size are they? How do you like your bras to feel?—rather than basing their fit decisions off a sizing chart.

As for consumers, Ruckman emphasizes the importance of trying out new bras on a run, rather than just bouncing around in a fitting room. (Brooks’s 90-day satisfaction guarantee allows for this. Reebok and Nike have a similar 30-day guarantees, and Lululemon says it will take back used items that customers aren’t happy with.) Jumping up and down may seem like a good way to judge a bra’s motion-reduction capabilities, but Ruckman points out that real-life running motion is very different. Plus, watching yourself do that in front of a mirror is misleading, she says, because “when you just start shaking your breasts, they’re gonna move. They should move!” No bra completely removes breast movement. The best ones minimize it and fit properly, and you are the only one who can ultimately judge the latter. “Don’t get stuck and engrained in a size,” she says. “Figure out how you want your bra to feel. Is the band too tight or too loose? Is the strap falling down or digging in? Is there gaping in your cup?”

Pinch points, restriction, and bulging at the side of the cup are the main things to avoid. A bra that fits well will have no excess fabric (your breasts totally fill the cups). The band and straps should be just tight enough that you can’t comfortably fit more than two fingers underneath them, and the band should also sit level all the way around, rather than riding up in the back.

Many running stores host their own group bra-fitting events. In some cases, motivated runners have taken matters into their own hands, like Dallas-based Alexandria Williams, who organizes regular bra-fitting events called Bras and Brunch, oriented specifically toward women who are plus-size or large chested.

The extra effort required to find a bra that fits is worth it. The first time I stepped away from sizing charts and bought a sports bra simply based on how it felt was in 2016, and it only happened because the opportunity fell directly into my path on my commute to a coffee shop. Lululemon was doing a trunk show at a yoga studio in town. On a whim, I stopped to flick through the racks and paused at the Energy bra, a pullover with thin, crisscrossed straps and a medium-coverage front. It was exactly the type of good-looking bra I was sure would never work for my chest. For some reason, I tried it on anyway. To my complete shock, it fit. The band hugged my rib cage securely. The cups offered enough coverage to prevent spillage without feeling like a heat trap and enough compression to keep everything roughly in place without screaming, “My boobs are so unruly I need a sport corset to strap them down!” And the straps—cute straps!

By that point in my life, I’d already skied off 12,000-foot peaks, run hundreds of high-altitude mountain miles, and climbed many thousands of vertical feet on rock. But wearing that bra, I felt like more of an athlete than I ever had before. This wasn’t simply because I liked the way I looked (though I did). It was because, for the first time, I didn’t feel like there was a part of my body that was wrong.

The bra didn’t support me any better than my old ones had. More than that: it wasn’t even enough to run in. But for everything else in my active lifestyle—skiing, rock climbing, yoga, hiking—it was more comfortable, and made me feel better about myself for it.

That purple bra, along with another identical one I bought in the following months, is still my favorite. But it’s far from the only one I wear. Emboldened by unexpected fit success, I opened myself up to trying on even more bras from even more brands until I’d amassed a core army of support systems that I loved for different activities: a high-impact run bra; several medium-impact models for slow runs, climbing, and hiking; and a low-impact number for multi-day trips (it’s so comfortable I can sleep in it). The options were out there, waiting for me to wake up and find them. And fortunately, they’re only getting better.

Art by Petra Zeiler