Blisters are the most common and most fixable running complaint. They come from two things together: moisture, which softens the skin, and friction, which rubs it. Take away either one and blisters mostly stop. Here is the order to fix things in, cheapest first.
Step 1: Get Rid of Cotton Socks
Cotton absorbs sweat and holds it against your skin, and it loosens and wrinkles when wet. That is both blister causes in one sock. Synthetic or merino running socks wick moisture away and hold their shape. This single change fixes a large share of beginner blisters.
Saucony RunDry No-Show Socks (6-Pack)
Six pairs of thin, fast-drying synthetic running socks for less than one premium pair. If you are currently running in cotton, start here - the difference is immediate.
Check Price on Amazon All sock picks
Balega Hidden Comfort No-Show
A seamless toe removes the ridge that rubs across the toes, and a deep heel pocket stops the sock creeping down inside the shoe. A long-standing running-shop answer for people who blister even in running socks.
Check Price on Amazon All sock picksStep 2: Check Your Shoe Size and Width
If you still blister in the same spot after changing socks, the shoe is usually the cause. Blisters on the tips of the toes or black toenails mean the shoe is too short — leave a thumb's width in front of the longest toe. Blisters on the sides of the foot mean it is too narrow; look for a wide fitting rather than sizing up. Blisters on the back of the heel usually mean the heel is slipping.
Step 3: Lock the Heel With Your Laces
Most running shoes have an extra eyelet at the top that nobody uses. It is for a heel-lock (or "runner's loop"): thread each lace through the top eyelet on the same side to make a small loop, then cross each lace through the opposite loop before tying. It pulls the shoe snugly around the ankle and stops the heel lifting, which fixes most heel blisters for free.
Step 4: Protect Hotspots on Long Runs
- Anti-chafe balm on known trouble spots reduces friction for a couple of hours.
- Tape or blister plasters applied before a run to a spot that always blisters work better than after.
- Keep feet dry on very long runs - some marathon and trail runners carry a spare pair of socks.
- Do not do long runs in brand-new shoes. Build up over a few shorter runs first.
When Merino Helps
Merino socks manage moisture better than synthetics on long and cold runs, and stay comfortable when damp. For blister-prone runners doing long distances, they are worth the premium.
Darn Tough Run No-Show Tab Ultra-Lightweight
A thin, dense merino running sock with light cushioning and a lifetime guarantee. It keeps feet comfortable across a wide range of temperatures and genuinely lasts years.
Check Price on Amazon All sock picksSwap cotton socks for synthetic or merino running socks. If blisters persist in one spot, check shoe length and width, and use a heel-lock lacing loop for heel blisters. On long runs, protect known hotspots before you start rather than after they hurt.
Frequently Asked Questions
Why do I get blisters when running?
Blisters form when moisture softens the skin and friction rubs it. Cotton socks, shoes that are too small or too narrow, heels that slip, and long runs in new shoes are the usual causes. Fixing the socks and the fit prevents most of them.
What socks prevent blisters?
Synthetic or merino running socks that fit snugly without wrinkles. Features that help include seamless toes, a deep heel pocket, and a raised heel tab on low socks. Avoid cotton.
Should I pop a running blister?
Generally, leave small intact blisters alone and cover them - the skin protects against infection. If a large blister is painful and likely to burst anyway, many runners drain it with a sterilised needle at the edge, leave the skin in place and cover it. Seek medical advice if it looks infected, and people with diabetes should not self-treat.
What is heel-lock lacing?
A lacing technique that uses the extra top eyelet on running shoes. You make a small loop on each side and thread the laces through the opposite loops before tying. It holds the heel firmly in the shoe and stops the slipping that causes heel blisters.