How to Prevent Chafing When Running

Few things end a good run faster than chafing. That raw, stinging feeling on your inner thighs, underarms or chest can turn a great session into a painful one, and it often only shows up in the shower afterwards. The good news: chafing is very preventable. Here's what causes it, where it happens and eight practical ways to stop it.

This guide offers general advice. If skin is broken, very painful or shows signs of infection, see a healthcare professional.

What Causes Chafing?

Chafing is skin irritation caused by repeated rubbing, either skin against skin or fabric against skin. Running repeats the same movement thousands of times, so even light friction adds up.

Three things make it worse:

  • Moisture. Sweat softens skin and increases friction, especially as salt dries on the skin.
  • Friction points. Rough fabric, bulky seams and loose clothing that moves around.
  • Duration and heat. Longer runs and hot weather mean more sweat and more repetitions.

Where Runners Chafe Most

  • Inner thighs
  • Underarms and the inside of the upper arms
  • Chest and nipples
  • Waistband and lower back
  • Under sports bra bands and straps
  • Feet (usually blisters, a close cousin of chafing)

8 Ways to Prevent Chafing

Choose synthetic, quick-dry fabrics

Cotton absorbs sweat and stays wet, which increases friction. Polyester and nylon blends wick sweat away and dry quickly, keeping skin drier. See our guide to the best fabric for workout clothes.

Get the fit right

Clothes that are too loose move and rub; clothes that are too tight dig in. Aim for a close, comfortable fit that stays in place as you run. For thigh chafing, slightly longer or fitted shorts, such as cycling shorts, can stop skin rubbing against skin.

Look for smooth, low-friction surfaces

Smoother fabric surfaces glide over the skin rather than catching on it. Many VYO running shorts and tees use a low-friction fabric surface designed to help reduce rubbing.

Mind your seams

Seams are common hot spots. Look for flat, smooth seams and check where they sit on your body, particularly at the inner thigh, underarm and waistband. 

Stay dry

Moisture is chafing's best friend. Quick-dry fabrics help, and on long runs you can carry a small towel or pause to dry hot spots.

Use a barrier balm

An anti-chafe balm or stick creates a slippery layer that reduces friction. Apply it to known hot spots before you run, and reapply on very long runs.

Test kit before race day

Never wear brand-new shorts, tops or bras for the first time on a long run or race. Test everything on shorter runs first.

Change out of wet kit fast

After your run, get out of sweaty clothes, shower and let your skin dry fully. Sitting in damp kit prolongs irritation.

Choosing Anti-Chafe Running Shorts

Look for shorts that combine:

  • Quick-dry, synthetic fabric to manage sweat.
  • 4-way stretch so the fabric moves with you instead of pulling.
  • A smooth, low-friction surface to reduce rubbing.
  • A fit and length that suit your body. If your thighs touch, consider a longer or fitted style.

VYO shorts are built around these principles, with 4-way stretch fabrics and low-friction surfaces. Explore men's shorts, women's shorts (including stretch cycling shorts) and 4-way stretch clothing.

When to See a Professional

Most chafing heals within a few days if you keep the area clean and dry and give it a break from friction. See a healthcare professional if the skin is broken and not healing, becomes very red, swollen or hot, or if you notice any signs of infection.

FAQs

1Q. What causes chafing when running?

Repeated friction between skin and skin, or skin and fabric, made worse by sweat, heat and long distances.

2Q. How do I stop my thighs chafing when I run?

Wear fitted or slightly longer shorts, such as cycling shorts, choose quick-dry fabric and use an anti-chafe balm on the inner thighs.

3Q. What shorts are best to prevent chafing?

Quick-dry shorts with 4-way stretch, smooth low-friction fabric and flat seams, in a fit and length that suit your body.

4Q. Does cotton cause chafing?

Cotton holds sweat and stays wet, which increases friction and makes chafing more likely on longer runs.

5Q. How do I treat chafing after a run?

Rinse gently, pat dry and let the area breathe. Avoid friction until it heals, and see a professional if it doesn't improve.

6Q. Can the wrong size cause chafing?

Yes. Clothes that are too loose move and rub, and clothes that are too tight dig in. A correct fit helps prevent chafing.

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