What is Chafing?

Chafing is skin irritation caused by repetitive friction—skin rubbing against skin, or skin rubbing against clothing. Long runs + sweat = the perfect storm for chafed skin.

Common Chafing Zones

The Usual Suspects

• 🦵 Inner thighs - The most common spot
• 👕 Nipples - Especially for men in cotton shirts
• 💪 Underarms - Where arms swing against torso
• 👙 Sports bra line - Seams and edges
• 🦶 Feet - Blisters are basically chafing

The Science of Chafing

Three factors combine to create chafing:

1. Friction - Repetitive rubbing motion
2. Moisture - Sweat breaks down skin's protective barrier
3. Pressure - Tight clothing or body parts pressing together

Prevention Strategies

Clothing Solutions

• 👕 Moisture-wicking fabrics - No cotton!
• 🏃 Seamless construction - Flat seams or none
• 🩳 Compression shorts - Prevent thigh rub
• 👚 Proper fit - Not too loose, not too tight

Anti-Chafe Products

Nipple Protection

• 🩹 NipGuards - Adhesive covers
• 🏷️ Medical tape - Cheap alternative
• 👕 Technical fabric - Softer on skin

Treatment

Mild Chafing

1. Clean gently with mild soap
2. Pat dry (don't rub!)
3. Apply healing ointment (Aquaphor, Neosporin)
4. Let it breathe when possible

Severe Chafing

• Clean carefully
• Apply antibiotic ointment
• Cover with non-stick bandage
• Take a break from running if needed
• See a doctor if signs of infection

The Bloody Nipple Phenomenon

Marathon photos are famous for showing runners with blood-stained shirts. This happens when:

• Cotton shirts + sweat + miles = nipple disaster
• Prevention is much better than the painful cure

Race Day Chafing Tips

1. Apply anti-chafe before you start - Generously!
2. Reapply at aid stations if needed
3. Wear race-tested clothing - Nothing new on race day
4. Consider the weather - More sweat = more risk
5. Body glide your feet - Inside socks for blister prevention

Chafing Math

Sweat + Friction × Miles = Pain
Prevention < Treatment

Chafing is one of those running problems that's 100% preventable but will absolutely ruin your day if you forget. A little Body Glide goes a long way.