Whip Six Womens Active Running, Triathlon, Cyclist Apparel

If your breasts could talk, they’d probably tell you that they’re not thrilled when they see you lacing up your running shoes. In fact, breast pain is an issue for almost one in three marathon runners, according to a new study published online in the British Journal of Sports Medicine. And the bigger your cup size, the more likely you are to be plagued with boob pain.

Researchers surveyed 1,285 female runners at the 2012 London Marathon Registration. The survey asked women about their exercise habits and workout intensity, as well as their medical history and how often they experienced breast pain. They found that 32 percent of women reported breast pain, but that number was strongly linked to the size of a woman’s bust. Pain was a problem for one in four women with A cups, but it was an issue for half of all women with a cup size of F or larger.

The big bummer: Working out is often to blame. Half of the women with breast pain said it was brought on by moderate exercise, and 64 percent said their girls hurt during vigorous exercise. Since nine out of 10 runners reported wearing sports bras while training, it’s not a total lack of support that’s the problem. According to experts, the real issue is that women aren’t getting the right support.

“Just because women are wearing sports bras doesn’t mean they’re wearing an appropriately fitting, supportive sports bra,” says lead study author Nicola Brown, PhD, lecturer in health and exercise at St. Mary’s University College in Twickenham, London.

To keep your breasts happy and healthy, try these expert-approved tips:

Get proper support all day—not just at the gym
While you don’t need to don a sports bra to run errands, you should still make sure your everyday bras give you the appropriate amount of support. “A lot of women probably don’t realize how active they are during their normal daily routine,” says study coauthor Joanna Scurr, PhD, head of the Research Group in Breast Health at the University of Portsmouth in London. “All types of activity can cause considerable breast movement, and ultimately our research has shown it’s the movement of the breast that can lead to pain.” Head to a department store or lingerie shop and meet with a bra-fitting specialist to find the right style and size for your bust.

Make sure your bra meets these expert standards
Pay attention to these five crucial bra-fitting points from the Research Group in Breast Health. They apply to both your sports bras and your everyday options:
• Band: It should be snug enough so it doesn’t slide around when you move but not so tight that it digs in or feels uncomfortable.
• Cup: If it has individual cups, your breasts should be contained in them, not spilling out in any direction. If the cups are puckering, you may need to go down a cup size.
• Underwire: If it has underwire, it should follow the natural crease of the breast rather than resting on it or digging in. If the underwire is resting farther down on your ribcage (where you’re a little narrower) the band might be too small.
• Front: The lower edge of your bra between the cups should lay flat against the body and not gape away from your chest. If the front is not laying flat, you may need to go up a cup size.
• Straps: They should provide support without digging into the skin. Your main support should come from a snug band, not super-tight straps.

Take your bra for a test drive
Once you’ve found a sports bra that seems to keep everything in place, make sure to test the support before you buy it. You could run laps around the store—or you could try this much subtler trick from Scurr: Do a few star jumps in the dressing room. Start with your feet together and your body squatted down with your hands on the floor. Then jump up while spreading you arms and legs out, like a star. This causes the same breast movement that occurs during running, says Scurr, so it’s an accurate way to gauge the fit. Another tip: Stretch your arms above your head and from side to side. “Your band should stay where it is when you put your arms up,” says Scurr.

Watch what you eat and drink
Some research has shown that a high-fat diet or excessive caffeine intake may contribute to breast pain in some people, says Dixie Mills, MD, breast surgeon at Harvard Vanguard Medical Associates. So if you’re feeling particularly sore, try cutting back on these to see if it makes a difference. Some experts also advise an anti-inflammatory diet—think tons of fresh fruits and veggies and limiting processed foods—to minimize pain from inflammation, says Mills. The bottom line: A healthier diet may help buffer against the breast tenderness, so eat clean if you’re experiencing soreness. And if you know you’re prone to pain around your period, take an over-the-counter pain reliever before a big workout, says Mills.

Keep exercising
It may sound counterintuitive since workouts can be the cause of discomfort, but staying fit can protect against breast pain in the long run. The study authors are currently working on two new studies that show an association between higher activity levels and lower levels of breast pain. So amp up your fitness routine to reap the benefits—just make sure you’re wearing a super-supportive bra first.

Need a few options? Check out our top picks for your girls from the Women’s Health 2013 Fitness Awards:

More from Women’s Health:
8 Rules of Sports Bra Shopping
The Best Sports Bra For Your Body
How to Choose a Painkiller

Whip Six Feed