In search of the perfect sports bra? You're not alone.
And the bustiest women are the worst off, according to international scientists who study the niche field of breast biomechanics. The most supportive bras for bigger-breasted women don't yet exist outside the lab.
While companies have long invested in running shoe and textile technology, innovation in bra construction has crawled along in comparison. In the past five years, however, the simple sports bra has increasingly attracted the attention of science.
"It's massively important because sports bra design is quite far behind other apparel," said Jenny White, a Ph.D. candidate at the U.K.'s University of Portsmouth who has led recent breast biomechanics studies. "Sports bras for women are just as important as shoes and socks that don't rub. … If we want to encourage more women to take part in sports, this is something that needs to be done."
If women feel uncomfortable or embarrassed about excessive jiggling, they won't take a trip to the gym, she said. And, especially as obesity rates climb in the United States and around the world, removing barriers to exercise becomes even more important.
In a recent study, White and her colleagues looked at the effects of different levels of breast support on running. They found that breast movement impacted women's running considerably -- the better the support, the less stressful the stride.
Without support, the researchers found that women hit the ground with more force, which may have negative physiological consequences on performance.
"In a no-bra condition, we found that there was more force being exerted on … the inside of the foot," she said. "Different bra support can affect the way we run."
White also said that research shows that when women run, their breasts don't just move up and down, but also side to side and forward and back.
"Breasts move in a figure eight while running," she said. "Sports bras in the past have not yet been designed to necessarily stop that movement."
And an ill-fitting bra isn't insignificant.
A bad bra can lead to neck pain, back pain and shoulder discomfort. Over time, researchers say, breast pain and breast sag can lead to lower self-esteem, less exercise and a decreased quality of life.
"There's so much more we can do with design," White said. "There are good bras out there if you look for them, but the optimal sports bra may not have been made yet."
One recent study from researchers at the University of Wollongong in New South Wales, Australia, actually found that the ideal design for women with larger breasts only exists in the laboratory.
Sports bras typically fall into two categories: Those that control movement by compressing the breasts or those that reduce motion by cupping each breast separately.
But the Australian researchers tested a third design. Using foam pads, they created an experimental bra that compressed and elevated the breasts as they might be buoyed in water.
Deirdre McGhee, a sports physiotherapist and researcher in the university's biomechanics laboratory, said her study showed that women more comfortably ran in the experimental bra, which provides greater compression and elevation (in addition to limiting vertical movement, which other bras already do), than the leading sports bra design.
McGhee said previous studies established that sports bras should control vertical movement but her research added two more elements.
"Maybe we need to also measure compression and also elevation," she said. "Maybe these are biomechanical factors that we should consider in sports bra design that may make women more comfortable."
After working with larger-breasted women (those who are 32E or 34DD and above), she said, she realized the need for a bra that would give them enough support to actually exercise. "Those women are in a vicious cycle," she said.
Their bras are uncomfortable, so they don't exercise but because they don't exercise, they don't decrease their body fat, which would also reduce the size of their breasts, thereby making exercise more comfortable.
To comfortably exercise, McGhee said, women with fuller busts likely need to wear two bras; a sports bra and a crop top.
"There probably isn't sufficient support on the market for those women," she said.
But although the ideal design doesn't exist for bigger-breasted women, women's health experts say that the average woman has a range of options when it comes to finding a supportive sports bra.
"Shapeware is such a burgeoning market, whether it's for fashion or for performance. You don't need to compromise anymore because there have been such leaps in technology," said Thea Palad, senior fashion editor for Women's Health Magazine.
But she said that finding the right buy for you requires some investment of time and money.
For starters, she said, get a sports bra fitting every year or every other year at a specialty lingerie store or section of a major department store.
Researchers say that 70 to 80 percent of women wear the wrong size bra, and Palad said that's likely true for sports bras too.
"Get a fitting and get fitted often," she said, adding that breast tissue changes depending on the time of the month and as people gain and lose weight.
She also said to think about what you'll be doing in the bra when you buy it. If you're doing yoga or tai chi, a super-supportive bra may not be as crucial as it is when you're doing kickboxing or going for a run.
"Obviously, it's always better to aim for higher impact activity as opposed to aiming lower," she said. "Err on the side of higher impact."
Your cup size is another key consideration. Smaller-breasted women often prefer compression bras, while women with fuller busts might opt for encapsulated bras which give each breast its own chamber, she said.
Palad also recommended trying out different strap styles. Racer-back and T-back bras may allow for more movement, but they often don't come with adjustable or padded straps featured on U-back bras, she said.
And when you're in the dressing room, she said, "definitely jump around, wiggle around."
"You can find the right one for you but you definitely have to look and you definitely have to test," she said.