Sweat and Skin Health: What You Need to Know

Sweat is not simply "gross" — it is a sophisticated system. Understanding what it actually is helps athletes manage their skin more effectively, because most sweat-related skin problems are caused by specific mechanisms that respond to specific solutions.

• Eccrine glands: distributed over the whole body, produce a dilute salt solution for thermoregulation. This is the majority of exercise sweat.
• Apocrine glands: found in armpits, groin, and areolae — produce a thicker fluid that bacteria break down into body odour. Activated by stress and emotion as well as heat.
• Sweat is mildly acidic (pH 4–6), which supports the skin's protective acid mantle and helps regulate the skin microbiome. Regular exercise may actually improve skin microbiome diversity.
• Miliaria (heat rash): blocked sweat ducts cause red, itchy bumps. Most common in hot, humid conditions or when skin is occluded (tight clothing). Treat by cooling the skin and avoiding occlusion.
• Timing of cleansing: cleanse as soon as possible after exercise — sweat left on skin for extended periods, combined with heat, increases pore-clogging and bacterial growth, particularly on the back and chest.