Diagonale des Fous

Race strategy

Hold a steady pace and save energy for every section.

• Big early climb with 1850m gain. Hold your pace, save your legs for later.
• 1514m descent. Go easy, save your quads.
• Final 714m descent. Save your legs to go all out on it.
• 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 138km, then run your race pace, and start the final descent from 169km under control, then go all out near the bottom.
• Start · 0.0km–1.5km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
• Settle in · 1.5km–27.4km · Climb of 1854m. Ease in: hold back more than feels necessary. The race is still ahead. Climb by heart rate or breathing, not pace.
• Work · 27.4km–92.1km · Descent of 435m averaging 8%, descent of 1514m averaging 13%, climb of 1220m. Plus 1 more climb. 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. Running pays off here: run wherever you can.
• Fade · 92.1km–169km · Descent of 1901m averaging 11%, climb of 1735m, descent of 1943m averaging 10%. Plus 2 more climbs and 1 descent. 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. Running pays off here: run wherever you can. Hike the steepest pitches. Your heart rate drifts down on its own: don't chase your early-race numbers, go by feel.
• Home · 169km–177km · Descent of 714m averaging 10%. No heroics: settle back into your own effort and hold it to the line. Very long descent: first half under control, then even, let go only near the end.

Course

The course climbs 10200m+. With 57m/km of climbing, this is a true mountain course with sustained climbs and descents. By gradient, 42% of the distance is uphill, 42% downhill and 17% flat. The longest climb runs 27.4km at an average 6.8% grade (1854m of vertical). The longest descent runs 18.7km at an average 10.4% grade (1943m of vertical). The steepest climb averages 43.9% over 0.3km. The steepest descent drops at 44.7% over 0.6km. Surface: 59% trail, 25% road, and 8% smooth. Flat-equivalent effort: 291.5 FlatKM.

Poles

Trekking poles are strongly recommended: about 18.1km of the course is steep enough for them to pay off.

Quad damage

Quad damage risk is high (index 78 of 100), with 35% of the load in the first half: 4 critical descents, the last of them run on already damaged legs. Downhill-specific preparation and a controlled early pace pay off here.

• Control your HR on the first climb, save your quads on the descents until 138km, then run your race pace, and start the final descent from 169km under control, then go all out near the bottom.
• #4 · 46.1–51.7 km · 435 m D−, -7.7% · 125.0 km ahead → control
• #1 · 67.1–78.4 km · 1514 m D−, -13.3% · 98.3 km ahead → control
• #2 · 92.1–109.1 km · 1901 m D−, -11.2% · 67.6 km ahead → control
• #3 · 119.2–137.9 km · 1943 m D−, -10.4% · 38.9 km ahead → control
• 169.3–176.7 km · 714 m D−, -9.7% · 0.0 km ahead → even, first half under control, let go at the end
• Plus 1 more notable descent not listed: your pace.

Weather

On race day, start temperatures have historically ranged from 22°C to 25°C, with around 7°C at the highest point; the chance of precipitation is about 33%.

Results

2,821 finishers completed the 2026 edition. Men's winner: Hugo Deck (France) in 22:54:19. Women's winner: Ruth Croft (New Zealand) in 27:13:23.