How to prevent chafing on your arms, boobs, and thighs

Marathon training is no joke-especially when it leaves you with scabs on your armpits or under your boobs. And I’ve experienced both.

By the time I got home, raw skin was literally poking through the hook-and-eye clips that ran up the bra's front.

Clearly, not something I wanted to ever happen again, which is why I chatted with some experts for their insights on what causes chafing, how to prevent it, and what to do if it's too late for any of that.

What the eff is chafing anyway?

By definition, “chafing is the process of rubbing skin against skin, or skin against fabric, causing red, irritated, painful skin in particular areas,” says Shari Lipner, M.D., Ph.D., assistant professor of dermatology at Weill Cornell Medicine. Sweat and moisture (say, from a rainy or ultra-sweaty run) up the likelihood of it happening.

So...how do I avoid it?

You want to keep your skin cool and dry, Lipner says. “Clothes should be form-fitting enough that they are not rubbing against skin," however, they shouldn’t be so tight that they start to dig into the skin either. Choosing tops and bottoms made with moisture-wicking materials will help you avoid this, too.

Seamless clothes are also a smart choice. Certified run coach and Mile High Run Club instructor Elizabeth Corkum, a.k.a. Coach Corky, says rough seams can do some damage. Luckily, many activewear brands have seam-free options.

It's also crucial to make sure your clothes simply fit right, according to Corkum. “When I went down a size in a sports bra, my sports bra band chafing completely stopped,” she says. “Turns out some fabrics expand when wet, and so the band would slide around slightly. After three hours of running, that caused big problems.” And on that note: You may want to try new gear on a shorter run, as well, rather than commit to hours in potentially uncomfortable clothes.

If you deal with arm or thigh chafing a lot, Corkum recommends Body Glide or Aquaphoron areas like you under arms or inner thighs. “It may not be necessary for every run, but probably long runs, or ones in wet or damp conditions,” she says. “You want to apply enough to coat the skin before a run. You can also use them after a run, before getting in the shower to help protect skin from the water.” (Because yeah, that shower is going to BURN if chafing has already occurred.)

How do I treat chafing if it does happen?

No matter what causes the arm or thigh chafing, make sure to clean it with a gentle soap and water post-sweat, says Lipner.

You can also rub an ointment on it, like petroleum jelly, to help speed up the healing. And of course, try to not to add any friction to the same area (a.k.a. don't set out on another long run the next day) so it has time to patch up, she says.

If the chafed skin doesn’t heal after a few days, Lipner suggests seeing a doc so they can help you treat it.