Best Trail Running Socks and Anti-Chafe Products

Most trail running blisters come from three sources: friction between the sock and skin (fixed by anti-chafe on hot spots before the run), sock bunching or seams that shift under load (fixed by a high-quality sock that maintains its shape), and wet feet from creek crossings or rain (fixed by either a waterproof sock or by accepting wetness and managing it with anti-chafe). Double-layer socks reduce friction by moving the sock-on-sock interface rather than sock-on-skin.

Merino wool manages moisture and odor better than most synthetics and retains warmth when wet, which matters on cold mountain trails. The tradeoff is durability; merino wears through faster than nylon unless it is tightly knit (Darn Tough uses a tight knit specifically to extend lifespan). For warm summer trails, performance synthetics (Balega) wick faster. For mountain racing and multi-day efforts, merino moisture management and blister resistance give it the edge.

Apply anti-chafe to all skin-on-skin and skin-on-gear contact points before the race starts and reapply at any crew point or aid station where you have time. Common points: inner thighs, underarms, nipples (men), bra line (women), the back of the neck where a vest sits, and the tops of feet around the ankle collar. Anti-chafe wears off with sweat and motion, and what feels fine at mile 10 can become a raw contact point by mile 40 without reapplication.

Yes, for runners who get inter-toe blisters, which are extremely common in trail running due to foot swell and toe-to-toe friction on descents. Injinji toe socks place a fabric layer between each toe that stops skin-on-skin contact. Some runners find the toe-pocket seams require a break-in period. They are not universally better than regular socks; they are specifically better for the inter-toe blister problem. Most ultramarathon runners who use them swear by them for 100-mile races.