As the weather warms up and humidity climbs, your body changes the way it behaves. You sweat more, your skin softens, and subtle swelling can occur in areas like your thighs, underarms, chest, or groin. Combine moisture with repetitive movement and friction, and chafing becomes an all-too-common side effect of running, walking, or any endurance activity.
The good news is that chafing is both preventable and treatable. Understanding why it happens can save you a lot of discomfort and keep small skin issues from turning into run-ending problems.
What causes chafing?
Chafing happens when friction repeatedly wears down the outer layer of your skin. This can occur in two main ways:
- Skin-on-skin friction, such as inner thighs, underarms, or between skin folds
- Fabric-on-skin friction, where seams, linings, straps, or loose clothing rub against the body
Sweat, rain, and humidity make things worse. Moist skin is softer and more vulnerable, which means friction does more damage more quickly. Long runs, hot conditions, or wet gear create the perfect environment for irritation to develop , especially in areas that move a lot or trap heat.
How to prevent chafing
Prevention starts before you even head out the door.
One of the simplest and most effective steps is to apply a barrier to common problem areas. Anti-chafing balms, sticks, or creams reduce friction by creating a smooth layer between skin and skin, or skin and fabric. Apply them generously to areas like inner thighs, underarms, chest, bra lines, or anywhere you’ve chafed before. If you’re heading out for a long run, carrying a small stick with you can be a lifesaver.
Despite what it might seem, well-prepared skin chafes less than dry skin. Keeping skin supple with a light moisturizer can actually reduce irritation, especially if you’re prone to dryness. Powders can help absorb moisture for some runners, but they’re usually best paired with a lubricant rather than used alone.
Clothing choice matters just as much. Opt for breathable, sweat-wicking fabrics that sit close to the body. Loose cotton may feel comfortable at first, but it traps moisture and moves around, which increases friction. Seamless, tag-free gear is ideal, especially for longer runs. If thigh chafing is an issue, longer inseams or compression-style shorts often make a big difference.
Pay attention to fit, particularly with sports bras and tops. Gear that’s too tight can dig in, while loose items can rub. For men, nipple chafing is a common problem on longer or wetter runs; tape or plasters can prevent a painful surprise later.
Finally, don’t overlook equipment-related chafing. Hydration packs, belts, heart-rate straps, and armbands can all cause irritation if they bounce or rub. Make sure everything is snug, and apply lubricant anywhere straps contact your skin.
How to treat chafing if it happens
Even with the best preparation, chafing can still occur, especially in extreme conditions. If you finish a run with irritated or raw skin, the goal is to calm, protect, and allow it to heal.
Start in the shower with lukewarm water. Hot water can intensify the burning sensation, while harsh scrubbing can make things worse. Gently cleanse the area with mild soap to reduce the risk of infection, then pat the skin dry rather than rubbing it.
Once dry, apply a soothing, protective ointment. Zinc oxide–based creams (often used for nappy rash) are particularly effective at calming inflammation and forming a barrier while the skin heals. Antibacterial ointments can also help if the skin is broken or very irritated.
For the rest of the day, wear loose, breathable clothing and give the area time to recover. Most chafing heals quickly if you remove friction and keep the skin protected, but it’s worth waiting until the area feels fully comfortable before running again.
The bottom line
Chafing isn’t a sign that you’re doing something wrong, it’s a common byproduct of movement, heat, and moisture. But with a little preparation, smart clothing choices, and quick treatment when needed, it doesn’t have to derail your training.
Identify your personal hot spots, be proactive on warmer or longer runs, and treat irritation early. Your skin will thank you, and you’ll spend more time running comfortably instead of wincing through every step.
