About Extreme Challenge
Extreme Challenge is the 45.4km skyultra at Absolute Biokovo Challenge 2025 (Makarska, Croatia). The race starts on May 10, 2025.
Race strategy
Hold a steady pace and save energy for every section.
- 482m descent. Go easy, save your quads.
- Steep 39% wall. Control your pace and stay focused.
- All downhill to the finish: go all out!
- Long race. Control your HR and effort. Early mistakes cost the most.
- Control your HR on the first mountain, save your quads on the descents until 28.0km, then run your race pace, and go all out on the final descent from 39.7km.
- Start · 0.0km–1.3km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
- Settle in · 1.3km–9.3km · Climb of 1111m. Ease in: hold back more than feels necessary. The race is still ahead. Climb by heart rate or breathing, not pace. Hike the steepest pitches.
- Work · 9.3km–23.0km · Descent of 482m averaging 16%, climb of 1582m. 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 · 23.0km–39.7km · Descent of 1220m averaging 24%, climb of 1576m, high point 1732m. 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. Hike the steepest pitches. Your heart rate drifts down on its own: don't chase your early-race numbers, go by feel.
- Home · 39.7km–43.5km · Descent of 358m averaging 9%. No heroics: settle back into your own effort and hold it to the line. Long descent: keep it even and let go only near the end.
Course
The course climbs 4480m+. With 99m/km of climbing, the course is exceptionally steep, with long hiking-grade sections. By gradient, 47% of the distance is uphill, 41% downhill and 8% flat. The longest climb runs 11.7km at an average 13.5% grade (1576m of vertical). The longest descent runs 5.0km at an average 24.5% grade (1220m of vertical). The steepest climb averages 41.9% over 0.8km. The steepest descent drops at 61.8% over 0.2km. Surface: 72% trail, 12% smooth, 6% technical, and 6% road. Flat-equivalent effort: 92.7 FlatKM.
Poles
Trekking poles are strongly recommended: about 11.1km of the course is steep enough for them to pay off.
Quad damage
Quad damage risk is moderate (index 35 of 100), with 42% of the load in the first half: 2 descents deserve a plan and a couple of downhill sessions before race day.
- Control your HR on the first mountain, save your quads on the descents until 28.0km, then run your race pace, and go all out on the final descent from 39.7km.
- #1 · 9.3–12.2 km · 482 m D−, -16.2% · 31.3 km ahead → control
- #2 · 23.0–28.0 km · 1220 m D−, -24.5% · 15.6 km ahead → control
- 39.7–43.5 km · 358 m D−, -9.3% · 0.0 km ahead → even, let go at the end
Results
19 finishers completed the 2025 edition. Men's winner: Sanjin Vucan (Croatia) in 7:39:43. Women's winner: Katja Kegl Vencelj (Slovenia) in 9:17:49.
This page has the full results and splits, a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for Extreme Challenge.
