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Grindstone Trail Running Festival by UTMB
169km169105km10552km52

Grindstone 100K

UTMB World Series
105.0km·2928m+
September 19, 06:00 AM
Swoope,
United States
utmb·source

Race Pace Calculator · GPX Analyzer · Trail Finder

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Read

  • How to Taper for a Marathon, Half Marathon or Ultra
  • Types of Runs and What Each Workout Actually Trains
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Full calendar: United States100K trail race calendar

Grindstone 100K · Race profile

Distance
105km
Gain
2928m+
FlatKM
126.5
Max
1313m
Min
408m

About Grindstone 100K

Grindstone 100K is the 105km ultra trail at Grindstone Trail Running Festival by UTMB 2026 (Swoope, United States). The race starts on September 19, 2026 at 06:00 AM.

Race strategy

Hold a steady pace and save energy for every section.

  • 634m 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.
  • Ease into the early runnable section, save your quads on the descents until 85.4km, then run your race pace.
  • Start · 0.0km–2.0km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
  • Settle in · 2.0km–18.4km · Plus 1 more climb. Ease in: hold back more than feels necessary. The race is still ahead. Climb by heart rate or breathing, not pace. Running pays off here: run wherever you can.
  • Work · 18.4km–54.5km · Climb of 672m, descent of 634m averaging 8%, climb of 750m. 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 · 54.5km–85.4km · Descent of 425m averaging 6%, climb of 631m, high point 1325m, descent of 1025m averaging 9%. 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 · 85.4km–105km · 19.3km 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 2928m+. With 28m/km of climbing, this is a rolling, mostly runnable course. By gradient, 33% of the distance is uphill, 31% downhill and 37% flat. The longest climb runs 17.4km at an average 4.3% grade (750m of vertical). The longest descent runs 11.0km at an average 9.3% grade (1025m of vertical). The steepest climb averages 28.7% over 0.4km. The steepest descent drops at 21.4% over 0.5km. Surface: 55% trail, 30% smooth, 11% road, and 5% extreme. Flat-equivalent effort: 126.5 FlatKM.

Summits

The highest summit on the course is Little Bald Knob (1320m), 74.4km from the start. Other named summits along the route: Hankey Mountain (1051m). The course also passes close to Sand Spring Mountain (1137m).

Poles

Poles bring little benefit here: only about 9.2km of pole-friendly terrain.

Quad damage

Quad damage risk is moderate (index 35 of 100), with 29% of the load in the first half: 3 descents deserve a plan and a couple of downhill sessions before race day.

  • Ease into the early runnable section, save your quads on the descents until 85.4km, then run your race pace.
  • #1 · 28.7–37.1 km · 634 m D−, -7.6% · 67.6 km ahead → control
  • #3 · 54.5–61.7 km · 425 m D−, -5.9% · 42.9 km ahead → control
  • #2 · 74.4–85.4 km · 1025 m D−, -9.3% · 19.3 km ahead → control

Weather

On race day, start temperatures have historically ranged from 9°C to 18°C, with around 18°C at the highest point; the chance of precipitation is about 33%. Heavy rain of 10.0mm or more falls on about 8% of days around this date.

Results

155 finishers completed the 2026 edition. Men's winner: Guillaume Hansel (United States) in 9:19:24. Women's winner: Rachel Doxey (United States) in 12:26:54.

This page has the full results and splits, a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for Grindstone 100K.

Other distances of Grindstone Trail Running Festival by UTMB 2026Grindstone 100M (169km)·Grindstone 50K (52.0km)

Other editions of Grindstone 100K2025

Official websitegrindstone.utmb.world