Istria 100 by UTMB® 69K

Race strategy

Hold a steady pace and save energy for every section.

• 329m descent. Go easy, save your quads.
• The finish is runnable. Save your legs to run it all the way.
• Control your HR on the first climb, save your quads on the descents until 24.1km, 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–14.2km · Descent of 329m averaging 11%. Plus 2 more climbs. Ease in: hold back more than feels necessary. The race is still ahead. 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.
• Work · 14.2km–29.6km · Climb of 465m, high point 400m, descent of 380m averaging 13%. Plus 1 more climb and 1 descent. 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.
• Fade · 29.6km–43.7km · Climb of 641m. Your energy fades, and that's normal: hold a steady effort and stop counting the miles. Climb by heart rate or breathing, not pace. Your heart rate drifts down on its own: don't chase your early-race numbers, go by feel.
• Home · 43.7km–68.8km · 25.1km 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 2331m+. With 33m/km of climbing, this is a rolling, mostly runnable course. By gradient, 27% of the distance is uphill, 32% downhill and 40% flat. The longest climb runs 14.1km at an average 4.6% grade (641m of vertical). The longest descent runs 2.9km at an average 11.3% grade (329m of vertical). The steepest climb averages 21.8% over 1.0km. The steepest descent drops at 27.0% over 0.2km. Surface: 40% smooth, 32% trail, and 22% road. Flat-equivalent effort: 83.4 FlatKM.

Summits

The course also passes close to Sv. Jure (384m), Pelegrin (185m), and Starola (165m).

Poles

Poles bring little benefit here: only about 9.5km of pole-friendly terrain.

Quad damage

Quad damage risk is moderate (index 29 of 100), with 71% 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 climb, save your quads on the descents until 24.1km, then run your race pace.
• #1 · 11.3–14.2 km · 329 m D−, -11.3% · 54.6 km ahead → control
• #2 · 21.2–24.0 km · 380 m D−, -13.4% · 44.8 km ahead → control

Weather

On race day, start temperatures have historically ranged from 8°C to 16°C, with around 13°C at the highest point; the chance of precipitation is about 39%. Heavy rain of 10.0mm or more falls on about 9% of days around this date.