Run long enough and far enough, and something will start to chafe. Maybe your thighs, maybe your bra straps, maybe some random spot that was never a problem on 10-mile runs but kills on a 12-miler. Here’s how to handle it.
Know what causes chafing
Chafing is skin irritation caused by rubbing. If you think about how many steps you’re taking every minute, and how many minutes you’re out on your run—it really adds up.
Moisture, including sweat, softens skin and makes it more prone to damage from rubbing. That’s why chafing is often worse in the summer months. If you’re in the habit of pouring water over your head to cool down, or if you run through streams on your trail runs, take care not to get any chafing-prone areas wet.
Anything can chafe, but it’s often the things you least expect, like straps or seams on clothing that were fine on short runs. Anything you plan to wear on a long run should be something you’ve worn on long or at least medium runs before, so you won’t have any sudden surprises.
The quickest solution is to buy yourself a stick of BodyGlide or a tub of Vaseline and use it anywhere you tend to get chafing. (Vaseline can stain some clothes, and isn’t appropriate for wetsuits if you happen to be into triathlons, so BodyGlide is the better all-around product.)
Apply before you go out, and if it’s a long run, consider bringing some with you to re-apply while you’re on the road. Marathons will often provide Vaseline (a volunteer will hand you a dab of it on a popsicle stick) at fluid stations or medical aid stations in the latter half of the course. Even in the middle of a run, you can smear it on the affected skin, and it should prevent further chafing.
If your thighs rub in short shorts, get a pair of longer shorts. (Bike shorts or compression tights are perfect for this.)
If you get chafing from seams or straps, look for seamless, tagless garments instead. Snug fitting clothes tend not to chafe because there just isn’t as much opportunity for rubbing. And sweat-wicking fabrics tend to help you stay dry, which also staves off chafing.
Use tape, but thoughtfully
Tape can protect skin, with a few caveats. The best use for it is on nipples, a common chafing spot for men. (Sports bras tend to avoid this problem for people with breasts. If you wear a bra and still get nipple chafing, a better-fitting bra may solve the problem.)
Applying tape on already-raw skin can irritate it further, so consider nipple tape or nipple guards, which are made for this purpose and usually have a gentler adhesive.
Tape can also cause chafing instead of preventing it, especially if the tape gets wet and then slips or wrinkles. And the surface of the tape can irritate the skin nearby. For example, one year I finished a long run before a half-marathon with some chafing on my upper arm that I thought was from armpit stubble. So on race day, I slapped a piece of kinesio tape (free from my swag bag!) onto the area that had chafed. My arm was fine, but the tape rubbed against my armpit during the race, and in the end I was worse off for it. In hindsight, I should have stuck with BodyGlide.