Training Socks: The Cheapest Fix for the Most Common Problem

A blister forms when skin layers shear against each other under repeated load. The sock either absorbs that movement or transmits it.

A cotton sock absorbs sweat, holds it against the skin, and loses its shape once wet. Softened skin shears at a fraction of the load dry skin tolerates.

Merino is the interesting one. It absorbs moisture into the fibre rather than holding it at the surface, so the skin stays comparatively dry even as the sock gets damp.

A technical sock in the wrong size will still blister you. Excess fabric folds and creates a ridge, and a sock stretched too thin loses its cushioning.

• The heel pocket should sit on your heel, not above or below it.
• No wrinkles anywhere when you stand — smooth it before lacing.
• Toe seam should sit across the toes, not on them.
• Size to the shoe you actually train in, not to your shoe size.

Foot health generally, including when a recurring problem is worth looking at properly, is covered by the American Podiatric Medical Association.

Crew socks earn their place in the weights room for one unglamorous reason: they protect the shin from a barbell during deadlifts, which most gyms would rather you did not bleed on.

More cushioning means more material between foot and shoe. That absorbs impact and reduces the space your foot has, which changes the fit of the shoe itself.

If you change cushioning level, re-check the shoe fit. A max-cushion sock in a shoe fitted with a thin one will feel a half-size too small.

A two-layer sock lets the layers move against each other rather than against your skin. It is the same principle as a two-piece short, applied to the foot.

They are bulkier and warmer, and for people who blister reliably on long sessions they solve the problem more consistently than any single-layer sock. The same logic in shorts is covered in our tight and compression shorts guide.

Worth knowing before you buy more socks. Several blister causes have nothing to do with what you are wearing.

If it is friction on skin rather than inside the shoe, the same principles apply as everywhere else — see our chafing guide.

Once socks are wet the fibre choice matters far more, because the foot will be in that state for the rest of the session.

• Never cotton in rain — it will not recover during the run.
• Thinner is better wet; thick socks hold water.
• Change immediately afterwards, before anything else.
• Dry shoes properly, or the next session starts damp.

The rest of the wet-weather picture is in our guide to training in the rain.

Socks take more abrasion than anything else you own and get washed more often. They are also the item most damaged by heat.

1. Wash inside out — the abrasion is on the inside.
2. Cool wash; elastic in the cuff is what fails first.
3. Never tumble dry if you want the cuff to keep gripping.
4. Retire when the heel thins, not when a hole appears.
5. Rotate; a pair worn every session lasts a third as long.

The same rules apply across the rest of the wardrobe — see our gym clothes care guide.

A separate category with a separate purpose, and one where the marketing runs some way ahead of the evidence.

The same honest summary applies as with compression shorts: the mechanical effects are real and the performance claims are not well supported. Our compression guide covers the evidence in more detail.

1. Stop wearing cotton. That alone fixes most blisters.
2. Fit the heel pocket and smooth out wrinkles before lacing.
3. Crew height for lifting, ankle for most training.
4. Re-check shoe fit if you change cushioning level.
5. Same spot every time means the shoe, not the sock.