If you're reading this, you've probably either finished a long day with skin that's raw and stinging, or you've got one coming up and you'd rather it didn't. Good news: chafing isn't bad luck, and it's very preventable once you know what's driving it. Here's the short version, then the why.
The short version
- Chafing is three things stacked: friction, moisture and time. Ease any one and it improves; deal with all three and it mostly disappears.
- The highest-value fix is a barrier product on the spots you know rub, applied before you start.
- Ditch cotton. Sweat-holding fabric is half the problem; merino moves sweat away and keeps working when damp.
- Fix anything that fits badly. A seam or waistband sitting over a moving joint becomes a chafe point no matter what else you do.
- Already raw? You can still put anti-chafe gel on afterwards to stop further rubbing and soothe it, then protect the spot next time.
What's actually happening to your skin
Your skin has a friction coefficient, which is just a number for how much it grips against whatever it's touching. When skin is dry, that number is low and things slide past. When skin gets damp, it climbs steeply. Research on skin against textiles has measured this directly: hydrated skin generates markedly more friction than dry skin against the same fabric (Gerhardt et al, 2008).
So sweat is the real problem. It's not that you're moving more, it's that every rub now grips harder and drags at the surface. Do that a few thousand times over a couple of hours and the outer layer gives up. That's the raw, stinging patch you find in the shower afterwards.
A 2025 systematic review of friction injuries in athletes puts a hard number on the moisture effect: wet cotton can more than double its friction compared to dry (Islam and Islam, 2025). Wet plus friction plus time is the whole problem in one line.
The three levers that actually work
Everything that stops chafing pulls one of three levers: cut the friction, manage the moisture, or fix the fit. Here's how to pull each.
Cut the friction. A barrier product sits between the two surfaces so they slide instead of grip. For most people this is the single highest-value change, because it's quick, cheap and works on skin you can't re-engineer. Put it on before you start, on the spots you already know rub. That's what our Anti-Chafe Gel is built for: 100% natural, goes on clean, stays put through sweat, and washes out of your kit afterwards. If you're weighing it up against Vaseline, we've compared the two properly here. And on the bike it's a slightly different job: saddle chafe is chamois cream territory, same idea, built for hours in the saddle.
Manage the moisture. Cotton is the enemy here: it soaks up sweat and holds it against your skin, which is the worst thing you can do given what moisture does to friction. Merino is the answer, in base layers and especially socks. It shifts moisture off your skin, keeps working when it's damp, and is hard to beat over a long day. On the feet, dry socks are one of the best anti-friction tools you have, and merino is what keeps them closest to dry.
Fix the fit. A seam parked over a moving joint, a waistband that rolls, a bra line that digs, these turn into chafe points no matter what else you do. Move the seam, size differently, or change the garment. It's the least glamorous lever and often the most permanent fix.
A simple pre-exercise routine
Apply a barrier product to your known hot spots before you get dressed, not once you're already 10km in and sore. Wear fabrics that move sweat rather than hold it. And on anything over a couple of hours, carry a small amount to reapply, because barrier products wear off with enough sweat and distance.
Already chafed? What to do now
Made the classic mistake and only thought about it once it started stinging? You can still use the gel after the fact. Smoothed over sore skin, it lays down a barrier that stops further rubbing for the rest of the day, and it's soothing on the raw patch. It's also made with mānuka oil, which is naturally antimicrobial. Clean the area, let it dry, then apply. Between sessions, keep the spot clean and dry, and protect it before your next one, because raw skin chafes faster than healthy skin.
Most chafe is a surface problem and settles down on its own within a few days. If a raw patch instead gets increasingly red, swollen, warm, weepy or painful over the following days, that can point to infection rather than normal healing, and it's worth getting it looked at by a health professional. Broken skin is an entry point, so don't ignore one that's heading the wrong way.
The bottom line
Chafing isn't bad luck, it's friction, moisture and time working against you, and all three are things you can change. Protect the spots you know rub, keep sweat moving off your skin, and sort anything that fits badly. Do that and long days stop ending with that particular sting.
This article is general information, not medical advice. If a skin problem is getting worse rather than better, see a health professional.
Sources
- Gerhardt LC et al. Influence of epidermal hydration on the friction of human skin against textiles. Journal of the Royal Society Interface, 2008;5(28):1317.
- Islam R, Islam KN. Cutaneous Friction Injuries and Blister Prevention in Athletes: From Stratum Corneum Mechanics to Smart-Textile Solutions: A Systematic Review. Premier Journal of Sports Science, 2025.