OCC

Race strategy

Hold a steady pace and save energy for every section.

• 777m descent. Go easy, save your quads.
• Steep 34% wall. Control your pace and stay focused.
• The finish is runnable. Save your legs to run it all the way.
• Long race. Control your HR and effort. Early mistakes cost the most.
• Control your HR on the first climb, save your quads on the descents until 38.2km, then run your race pace.
• Start · 0.0km–1.9km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
• Settle in · 1.9km–12.5km · Climb of 632m. Ease in: hold back more than feels necessary. The race is still ahead. Climb by heart rate or breathing, not pace. Running pays off here: run wherever you can. Hike the steepest pitches.
• Work · 12.5km–32.5km · Climb of 713m, descent of 777m averaging 14%, climb of 1069m. This is where the race is built: steady, solid effort. Climb by heart rate or breathing, not pace. This descent is hard on the legs: short steps, stay in control, poles if you have them. Hike the steepest pitches.
• Fade · 32.5km–49.0km · Descent of 569m averaging 10%, high point 2298m, descent of 851m averaging 12%. Plus 1 more climb. Your energy fades, and that's normal: hold a steady effort and stop counting the miles. Climb by heart rate or breathing, not pace. This descent is hard on the legs: short steps, stay in control, poles if you have them. Your heart rate drifts down on its own: don't chase your early-race numbers, go by feel.
• Home · 49.0km–59.6km · 10.6km of runnable trail. No heroics: settle back into your own effort and hold it to the line. Running pays off here: run wherever you can.

Course

The course climbs 3500m+. With 58m/km of climbing, this is a true mountain course with sustained climbs and descents. By gradient, 40% of the distance is uphill, 36% downhill and 24% flat. The longest climb runs 9.4km at an average 11.3% grade (1069m of vertical). The longest descent runs 6.9km at an average 12.3% grade (851m of vertical). The steepest climb averages 33.4% over 0.4km. The steepest descent drops at 34.1% over 0.5km. Surface: 65% trail, 16% road, 12% smooth, and 8% technical. Flat-equivalent effort: 86.7 FlatKM.

Summits

The highest summit on the course is L'Arolette (2330m), 34.7km from the start. Other named summits along the route: Tête de Balme (2321m).

Poles

Trekking poles are strongly recommended: about 6.5km of the course is steep enough for them to pay off.

Quad damage

Quad damage risk is moderate (index 40 of 100), with 38% of the load in the first half: 3 descents deserve a plan and a couple of downhill sessions before race day.

• Control your HR on the first climb, save your quads on the descents until 38.2km, then run your race pace.
• #1 · 17.3–23.1 km · 777 m D−, -13.6% · 36.6 km ahead → control
• #2 · 32.5–38.2 km · 569 m D−, -9.9% · 21.4 km ahead → control
• #3 · 42.1–49.0 km · 851 m D−, -12.3% · 10.6 km ahead → your pace

Weather

On race day, start temperatures have historically ranged from 11°C to 20°C, with around 13°C at the highest point; the chance of precipitation is about 46%. Heavy rain of 10.0mm or more falls on about 11% of days around this date.

Results

1,563 finishers completed the 2026 edition. Men's winner: Frédéric Tranchand (France) in 5:10:08. Women's winner: Lauren Gregory (United States) in 6:08:07.