Photo: Wikimedia Commons (CC BY-SA 2.5) / Source (opens in a new tab)Saint-Leu-la-Forêt
Les 40 Bosses
Saturday, 5 December 2026
Le Monstre 120K
120km D+ 5500m
La Belle 75K
75km D+ 3300m
L'Historique 45K
45km D+ 2100m
La Classique 20K
20km D+ 900m
Le Sprint 10K
10km D+ 400m
Les 40 Bosses 2026: Registration
Les 40 Bosses is Paris's big winter trail: 10 to 120 km and up to 5,500 m D+ in the Montmorency forest, 25 km from the capital, on the first weekend of December.
Registration not open yet
Visit official website ↗(opens in a new tab)Entry fees by distance
| Distance | Elevation | Price | |
|---|---|---|---|
| Le Monstre 120K120K | 5,500m D+ | Check website | Coming soon |
| La Belle 75K75K | 3,300m D+ | Check website | Coming soon |
| L'Historique 45K45K | 2,100m D+ | Check website | Coming soon |
| La Classique 20K20K | 900m D+ | Check website | Coming soon |
| Le Sprint 10K10K | 400m D+ | Check website | Coming soon |
How to register
- 1
Go to the official race website using the registration button.
- 2
Select the distance you want to run.
- 3
Fill in the form with your personal details and federation license (if required).
- 4
Complete the payment and save your registration confirmation.
What's included in your entry?
Race bib with timing chip, aid stations along the course, accident insurance during the race, access to finish line services (physiotherapy, showers, finisher meal) and an event t-shirt or memento.
Registration not open yet
The organizer hasn't activated online registration yet. Check the official website to stay up to date on the opening.
Visit official website ↗(opens in a new tab)More races in December 2026

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