Date
Sun, 6 Dec 2026
Start
08:30
Venue
Rue du Général Leclerc and Rue des Ecoles, Saint-Leu-la-Forêt
Saint-Leu-la-Forêt, Val-d'Oise
Countdown
December
L'Historique is the original Les 40 Bosses route, a 45 km daytime loop with 2,000 m of climbing. A solid first step into ultra-length trail, with all the daylight you need.
Key facts
018-hour cut-off
02Valid athletics licence or FFA PPS required, minimum age 19
Create a free training plan for the Les 40 Bosses 45 km
7-day free trial, no card required
The course
The route
Saint-Leu-la-Forêt
Distance45km
Total climb2,000m
StartElevation
0 kmDrag map to rotate40.5 km
Weather
Early-December, Saint-Leu-la-Forêt
7°CTypical high
1°CTypical low
-7°CColdest in 20 years
41%Days with rain
Highs around 7°C and lows around 1°C, but it has dropped to -7°C. Rain on 41% of days. Pack for the cold end, not the average.
NASA POWER data, 2006-2025, the week either side of race day
2025 results
Who finishes, and how
#RiderTimeAvg speed
01Maria LABARRE06:06:037.4 km/h
02Sindy FALDUTI06:08:557.3 km/h
03Camille MASSIMI06:15:327.2 km/h
46
Women finishers
7:38:26
Median time
5.9 km/h
Median speed
Women · 2025 results, as published by the organiser.
How fast could you finish?
Get a prediction based on your recent training
Organiser
Training
Training for the Les 40 Bosses 45 km
We don't do generic plans. We combine deep knowledge of this race's demands with your recent training, then build a plan with you that progresses as you do.
Beina integrates directly with your existing tools to understand your current fitness, and synchronise your planned sessions.
Intervals.icuWhat a Les 40 Bosses 45 km plan targets
Typical sessions
45 km with 2,000 m of climbing
Time on feet and fatigue resistance
Fuelling and pacing for the whole event
What your weeks look like
Typical sessions
Long runs that build time on your feet
Tempo and threshold sessions to hold race pace
Hill reps and vert to prepare the climbs and descents
Back-to-back weekend runs for fatigue resistance
Not a generic schedule
Typical sessions
Built from your current fitness and the time you actually have
Adapts every week as Beina learns how you respond
Syncs your sessions straight to Garmin and Wahoo
One clear next session, never a wall of spreadsheet
Entries open now
Get your Les 40 Bosses 45 km plan.
7-day free trial, no card required.
More events in December in France
MENESTRAILSat, 5 Dec 2026 · Moncontour→L'Hivernale des TempliersSun, 6 Dec 2026 · Roquefort-sur-Soulzon→L'Hivernale des Templiers – Marathon de l'OrchisSun, 6 Dec 2026 · Start: in front of the church→Trail de Ménilles Vallée d'EureSun, 6 Dec 2026 · Ménilles→Trail de Noël des SaisiesExpected Early December 2026 · Hauteluce→Genep'TrailSat, 12 Dec 2026 · Huez→
