When packing your kit bag for the UTMB®, your clothing choices are decisive: they must shield you from harsh weather while delivering relentless comfort over long distances. Plan your race outfit well in advance—ideally several months before the event—so you can test it thoroughly in real-world conditions.
Mandatory waterproof clothing
UTMB® regulations require a waterproof jacket and trousers in your pack at all times to protect against severe mountain weather (rain, snow). They must meet strict standards, including a minimum waterproof rating of 10,000 Schmerber (mm) and a RET breathability rating below 13. Your gear may be checked before the start: without compliant waterproof kit, you will not be allowed to race. Choose carefully—gear quality is crucial when mountain conditions turn harsh.
Explore our selection of waterproof trail jackets.
Other mandatory clothing required by race rules
A waterproof jacket is not the only compulsory item, and missing kit is common during inspections. Race rules also require:
- A warm, long-sleeved mid-layer made of technical fabric—strictly no cotton—weighing a minimum of 180 g for a men's size M.
- A pair of full-length running trousers or running tights, in addition to waterproof overtrousers.
- Warm, waterproof gloves.
- A beanie.
- A cap or neck gaiter/buff for sun protection.
Pay close attention to the 180 g threshold: many lightweight trail mid-layers fall below this limit and will fail kit check. Always verify the manufacturer's declared weight before buying. Explore our trail mid-layers for men and women.
The thermal jacket
To cope with shifting mountain temperatures, a good thermal jacket must be breathable: otherwise, sweat cannot escape, creating an uncomfortable greenhouse effect. Choose a trim fit that is not overly tight to ensure full freedom of movement, especially around the arms.
Explore our selection of trail and running jackets.
The technical t-shirt
Opt for a technical t-shirt engineered for long-distance efforts: lightweight fabric that rapidly wicks away sweat and dries fast, preventing that clingy, damp feeling over time. High breathability also limits overheating and odour build-up over hours of racing—a key factor for an ultra like the UTMB®.
Explore our selection of trail running t-shirts.
Trail shorts and trousers
When it comes to shorts or trousers, choose stretch fabrics that follow every stride without restriction, delivering true freedom of movement from start to finish. Breathability and quick-drying fabrics prevent moisture build-up over time, while lightweight construction goes unnoticed even after hours on the trail. A well-designed waistband and integrated pockets let you carry your essentials without hindering your stride.
Explore our selection of trail shorts and trousers.
Frequently asked questions
What clothing is mandatory for the UTMB®?
A hooded waterproof jacket with a minimum 10,000 Schmerber rating, waterproof overtrousers, full-length trousers or running tights, a warm long-sleeved mid-layer weighing at least 180 g, warm waterproof gloves, a beanie, and a cap or buff.
Is cotton allowed for the mid-layer?
No. Race regulations strictly ban cotton, as it traps moisture and quickly chills the runner once movement stops.
Find out more
- Mandatory kit for the UTMB®
- Choosing your shoes for the UTMB®
- Essential accessories for the UTMB®
- Nutrition and hydration for the UTMB®
Photo credits: Clément Dumas, Delphine Daniélou.
