What to wear on a long-distance trail run

Updated: September 2026

Collage of the recommended running kit for these conditions, with specific clothing and accessory models

Short answer

In these conditions (about 6 °C air temperature), running will feel like about 4 °C. This is the recommended kit:

Rule of thumb: running makes you feel 5-8 °C warmer than the thermometer says. Dress for how you will feel once moving, not for the air temperature.

Long-distance trail: dress for hours, not minutes

On a long trail the challenge is not the first kilometre but kilometre fifty: temperature, altitude, pace and your fatigue all change. Dress for the coldest weather you might meet and carry layers to adjust over hours.

A trail vest with a windbreaker, waterproof jacket, hat, gloves and a light thermal layer is the core of the mandatory kit at most races. When tired you generate less heat and feel the cold more, especially at night.

Nutrition and hydration are part of the kit: bottles or soft flasks, gels, salts and some solid food. And look after your body: anti-chafe balm, spare socks and an extra buff weigh little and can save your race.

Recommended kit, item by item

Head and neck

Thermal buff or thin beanie. You lose a lot of heat through head and neck, and it fits in a pocket once you warm up.

Torso

Long-sleeve thermal base layer that wicks sweat. It is the piece that makes the biggest difference.

Outer layer

Light windbreaker (100-140 g): it stops the air, which is what cools you most when running, and packs tiny.

Legs

Technical full-length tights. Cold muscles get injured more: do not gamble with shorts.

Hands

Thermal gloves with good grip for poles. With cold hands it is hard to open gels and zips.

Feet

Merino or thermal socks, well fitted: any extra fabric causes blisters.

Backup kit

Long run: pack a thermal blanket, a windbreaker and a dry buff. The cold arrives when you stop, not while you run.

Adjust to your case: calculator with wind, rain, pace and duration →Change the temperature and conditions and the kit updates instantly.

Frequently asked questions

What should I wear on a trail longer than 6 hours?

A technical tee, windbreaker, waterproof jacket, hat and light gloves. Add a spare thermal layer if there is night or altitude.

How many layers should I carry in an ultra?

A base layer, a light thermal layer and a waterproof, windproof outer layer. With fatigue and altitude, perceived temperature drops a lot.

What should I carry in my pack besides clothing?

Water, food, a thermal blanket, headlamp, whistle and phone. Most race rules require it; check the mandatory kit before every race.