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Grindstone Trail Running Festival by UTMB
169km169105km10552km52

Grindstone 100M

UTMB World Series
169.0km·5532m+
September 18, 06:00 PM
Swoope,
United States
utmb·source

Race Pace Calculator · GPX Analyzer · Trail Finder

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Read

  • Types of Runs and What Each Workout Actually Trains
  • Hill Training for Trail Runners: Train the Descents
  • Downhill Running Muscle Damage: Why Descents Wreck Quads

Full calendar: United States100-mile trail race calendar

Grindstone 100M · Race profile

Distance
169km
Gain
5532m+
FlatKM
229.3
Max
1324m
Min
405m

About Grindstone 100M

Grindstone 100M is the 169km ultra trail at Grindstone Trail Running Festival by UTMB 2026 (Swoope, United States). The race starts on September 18, 2026 at 06:00 PM.

Race strategy

Hold a steady pace and save energy for every section.

  • 1005m 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 114km, then run your race pace.
  • Start · 0.0km–1.5km · Race-day nerves push your heart rate up: don't follow the crowd, find your own rhythm.
  • Settle in · 1.5km–27.8km · Climb of 631m. 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 · 27.8km–85.6km · Descent of 1005m averaging 9%, descent of 542m averaging 6%, descent of 382m averaging 8%. Plus 2 more climbs. 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.
  • Fade · 85.6km–148km · Descent of 727m averaging 9%, high point 1329m, descent of 519m averaging 9%, climb of 631m. Plus 2 more climbs and 1 descent. 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 · 148km–167km · 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 5532m+. With 33m/km of climbing, this is a rolling, mostly runnable course. By gradient, 38% of the distance is uphill, 35% downhill and 28% flat. The longest climb runs 10.2km at an average 5.2% grade (534m 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 26.4% over 0.3km. Surface: 66% trail, 27% smooth, and 7% road. Flat-equivalent effort: 229.3 FlatKM.

Summits

The highest summit on the course is Little Bald Knob (1320m), 137km from the start. Other named summits along the route: Hankey Mountain (1051m). The course also passes close to Door Knob (1038m).

Poles

Poles bring little benefit here: only about 17.4km of pole-friendly terrain.

Quad damage

Quad damage risk is high (index 62 of 100), with 44% of the load in the first half: 5 critical descents, the last of them run on already damaged legs. Downhill-specific preparation and a controlled early pace pay off here.

  • Ease into the early runnable section, save your quads on the descents until 114km, then run your race pace.
  • #1 · 42.0–52.7 km · 1005 m D−, -9.4% · 114.6 km ahead → control
  • #2 · 66.6–75.6 km · 542 m D−, -6.0% · 91.8 km ahead → control
  • #4 · 81.0–85.6 km · 382 m D−, -8.4% · 81.8 km ahead → control
  • #3 · 89.8–97.7 km · 727 m D−, -9.2% · 69.7 km ahead → control
  • #5 · 107.9–113.6 km · 519 m D−, -9.1% · 53.8 km ahead → control
  • 137.1–148.0 km · 1025 m D−, -9.3% · 19.3 km ahead → your pace

Weather

On race day, start temperatures have historically ranged from 18°C to 27°C, with around 17°C at the highest point; the chance of precipitation is about 31%. Heavy rain of 10.0mm or more falls on about 7% of days around this date.

Results

121 finishers completed the 2026 edition. Men's winner: Jordan Buck (United States) in 20:58:15. Women's winner: Katti Jackson (United States) in 21:46:37.

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 100M.

Other distances of Grindstone Trail Running Festival by UTMB 2026Grindstone 100K (105km)·Grindstone 50K (52.0km)

Other editions of Grindstone 100M2025

Official websitegrindstone.utmb.world