How to Prevent Running Blisters: A Complete Guide

Blisters form when friction, moisture, and heat combine on your skin. They are the most common running complaint and can turn a great training block into a painful slog. Prevention is straightforward once you understand the causes.

Why Blisters Form

Repetitive friction between your skin and sock or shoe creates shear forces in the upper layers of skin. Fluid fills the gap, forming a blister. Moisture from sweat or rain softens skin and increases friction. Hot spots that feel warm during a run are blisters in progress.

Sock Selection

Socks are your first line of defense. Choose moisture-wicking synthetic or merino wool socks, never cotton. Cotton absorbs sweat and stays wet, dramatically increasing friction. Balega, Darn Tough, and Feetures make excellent running-specific socks with reinforced friction zones.

Shoe Fit

A shoe that is too tight creates pressure points. Too loose allows your foot to slide and generate friction. You should have a thumb’s width of space between your longest toe and the shoe tip. Your heel should lock firmly without slipping.

Lacing Techniques

A heel lock lacing pattern eliminates heel slippage without tightening the entire shoe. Loop each lace through the extra top eyelet to create a lock before tying. This single change prevents the most common blister location for runners.

Lubrication and Taping

Apply a thin layer of Body Glide or petroleum jelly to blister-prone areas before running. For known trouble spots, apply Leukotape or moleskin before the run rather than after the blister forms. Prevention tape stays on through sweat and long distances.

Moisture Management

Apply foot powder before long runs in humid conditions. Change socks at aid stations during ultramarathons. Some runners carry a lightweight spare pair for any run over two hours in wet conditions.

When Blisters Happen

If a blister does form, avoid popping it unless it affects your gait. The fluid protects healing skin underneath. If you must drain it, sterilize a needle, puncture at the base, press gently, and cover with a hydrocolloid bandage.