Men's technical trail underwear

The base layer

In trail running, the technical underwear, or base layer, is in direct contact with the skin. Its role is to wick sweat away to the outer layers to keep the skin dry: wet skin cools down quickly, especially at the summit or during descents, and leads to irritations. Cotton, which retains moisture, should be avoided. Technical materials, whether synthetic or made from merino wool, dry quickly and keep the body at a good temperature.

The other clothing

Men's trail wear also comes in:

• T-shirts and tops.
• Jackets and windbreakers.
• Shorts and tights.
• Trousers and leggings.
• Sweatshirts.
• Socks and ankle socks.

All the clothing is gathered on the men's clothing page.

Merino or synthetic

Merino wool, with very fine fibers that don’t itch, regulates temperature, stays warm even when wet, and naturally limits odors: perfect for long races and multi-day ultras. Synthetic fibers, like polyester or polyamide, dry faster and withstand wear better: ideal for intense outings and heat. Some tops combine both to bring together their advantages.

Body vests and boxers

The long-sleeved body vest, close-fitting, can be worn alone in cool weather or under a jacket in winter; the short-sleeved version is suitable for mid-seasons. The technical boxer, seamless or with flat seams, prevents chafing in the groin area over long distances and features a supportive pouch. Choose a fitted cut, without excessive compression. Wash your underwear at thirty degrees, without fabric softener, and merino wool on the wool programme.

Good deals

Good deals can also be found in good plans, promotions, clearance, sales, and Black Friday. The new arrivals showcase the latest collections, and items shipped in 24h are prepared and sent within 24 hours. The key events of the year follow a stable order: the Black Friday at the end of autumn, the holiday season, the winter sales, the French Days in spring, followed by the summer sales and back-to-school season.

Frequently asked questions

What underwear to wear for trail running in cold weather?

A long-sleeved body vest, made of merino wool or thick synthetic material, keeps warmth while wicking sweat away. Add a mid-layer and a windbreaker depending on the altitude.

Why a boxer without seams for running?

The seams rub at the groin area and cause irritation over long distances. A seamless, well-fitted, and breathable boxer stays in place and prevents chafing.

How to avoid chafing on an ultra-trail?

Wear fitted and seamless underwear, apply anti-chafing cream on sensitive areas before starting, and change into dry clothes at aid stations if possible.

Should you layer two layers under the windbreaker?

In winter or in the mountains, yes: the first layer wicks sweat and the second insulates against the cold. In summer, a single technical t-shirt is sufficient, as an extra layer traps heat and sweat.

How to wash merino underwear?

Wash them in cold water, on the wool programme, without fabric softener, then dry flat. Merino naturally limits odors: often, just airing them between outings is enough.