Jeju 100K

Race strategy

Hold a steady pace and save energy for every section.

• Big early climb with 1690m gain. Hold your pace, save your legs for later.
• 1078m descent. Go easy, save your quads.
• 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 mountain, save your quads on the descents until 60.4km, then run your race pace.
• Start · 0.0km–1.2km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
• Settle in · 1.2km–22.7km · Climb of 1688m. 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 · 22.7km–48.7km · Descent of 1078m averaging 10%, climb of 1409m, high point 1913m. 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. Hike the steepest pitches.
• Fade · 48.7km–94.2km · Descent of 1277m averaging 11%. Plus 2 more climbs and 2 descents. 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. Your heart rate drifts down on its own: don't chase your early-race numbers, go by feel.
• Home · 94.2km–102km · 8.3km 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 4000m+. With 38m/km of climbing, this is a rolling, mostly runnable course. By gradient, 36% of the distance is uphill, 38% downhill and 27% flat. The longest climb runs 22.7km at an average 7.4% grade (1688m of vertical). The longest descent runs 11.7km at an average 10.9% grade (1277m of vertical). The steepest climb averages 33.8% over 0.5km. The steepest descent drops at 30.7% over 0.9km. Surface: 52% trail, 24% road, 10% smooth, and 8% technical. Flat-equivalent effort: 139.9 FlatKM.

Poles

Poles bring little benefit here: only about 14.4km of pole-friendly terrain.

Quad damage

Quad damage risk is moderate (index 47 of 100), with 51% 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 60.4km, then run your race pace.
• #1 · 22.7–33.0 km · 1078 m D−, -10.4% · 69.4 km ahead → control
• #2 · 48.7–60.4 km · 1277 m D−, -10.9% · 42.1 km ahead → control
• 75.0–81.3 km · 298 m D−, -4.7% · 21.1 km ahead → your pace
• 84.6–94.2 km · 531 m D−, -5.5% · 8.3 km ahead → your pace

Weather

On race day, start temperatures have historically ranged from 19°C to 24°C, with around 10°C at the highest point; the chance of precipitation is about 30%. Heavy rain of 10.0mm or more falls on about 10% of days around this date.

Results

950 finishers completed the 2026 edition. Men's winner: Ruqin Wang (China) in 10:11:33. Women's winner: Lingjie Chi (China) in 12:15:06.