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Julian Alps Trail Run by UTMB
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INTERSPORT SPEED 15K

UTMB World Series
15.0km·550m+
September 19
Kranjska Gora,
Slovenia
source

Race Pace Calculator · GPX Analyzer · Trail Finder

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Full calendar: Slovenia

INTERSPORT SPEED 15K · Race profile

Distance
15.0km
Gain
550m+
FlatKM
21.1
Max
1010m
Min
739m

About INTERSPORT SPEED 15K

INTERSPORT SPEED 15K is the 15.0km trail race at Julian Alps Trail Run by UTMB 2025 (Kranjska Gora, Slovenia). The race starts on September 19, 2025.

Race strategy

Run easy on the first mountain, then go all out on the second.

  • Start easy and control your HR up to 7.7km.
  • Hold your race pace up to 11.6km, but stay in control.
  • All downhill to the finish: go all out!
  • Control your HR on the first mountain, then run your race pace, and go all out on the final descent from 11.6km.
  • Start · 0.0km–2.1km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
  • Settle in · 2.1km–7.7km · Climb of 221m, high point 1011m. Plus 1 more descent. Ease in: hold back more than feels necessary. The race is still ahead. Climb by heart rate or breathing, not pace.
  • Work · 7.7km–11.6km · Plus 1 more climb. This is where the race is built: steady, solid effort. Climb by heart rate or breathing, not pace.
  • Home · 11.6km–17.1km · Descent of 200m averaging 4%. Build to the finish: leave whatever you have left out on the course.

Course

The course climbs 550m+. With 37m/km of climbing, this is a rolling, mostly runnable course. By gradient, 31% of the distance is uphill, 24% downhill and 46% flat. The longest climb runs 5.0km at an average 4.4% grade (221m of vertical). The longest descent runs 5.4km at an average 3.7% grade (200m of vertical). The steepest climb averages 34.2% over 0.3km. The steepest descent drops at 16.4% over 0.3km. Surface: 59% trail and 39% road. Flat-equivalent effort: 21.1 FlatKM.

Poles

The course is runnable enough that trekking poles are not needed.

Quad damage

Quad damage risk is low (index 8 of 100): a few descents worth noting, none of them decisive.

  • Control your HR on the first mountain, then run your race pace, and go all out on the final descent from 11.6km.

Weather

On race day, start temperatures have historically ranged from 9°C to 18°C, with around 13°C at the highest point; the chance of precipitation is about 42%.

Results

627 finishers completed the 2025 edition. Men's winner: Adrian Brănescu (Romania) in 1:14:18. Women's winner: Julia Rath (Germany) in 1:27:29.

This page has the full results and splits, a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for INTERSPORT SPEED 15K.

Other distances of Julian Alps Trail Run by UTMB 2025I Feel Slovenia 120K (124km)·Lake Bled 80K (80.0km)·Sky Trail 50K (50.0km)·Kranjska Gora 25K (25.0km)·FUNNY 10K (10.0km)

Other editions of INTERSPORT SPEED 15K2026

Official websitejulianalps.utmb.world