Skip to content
Endurance AnalyticsEndurance Analytics
  • Calendar
  • Trail Finder
  • Geo Quiz
  • Blog
  • Trail Buddy
Trail runningBiathlonSkiingSkimoOlympicsCalendarTrail FinderGPX AnalyzerRace Pace CalculatorChallengesTrail BuddyComparePricingConnect AIBlog

Know the course before you run it

© 2026 Endurance Analytics. All rights reserved.

Privacy policyTerms of serviceRefundsContact
  1. Home
  2. Trail running
  3. 2025
  4. Quad Rock
Quad Rock
81km8140km40

Quad Rock 50mi

81.0km·3060m+
May 10
Fort Collins,
United States
itra

Race Pace Calculator · GPX Analyzer · Trail Finder

Other races: United States

  • Dead Horse Ultra · Dead Horse 50 MileNovember 14, 2026 · 80.5km · 1492m+
  • Dead Horse Ultra · Dead Horse 50KNovember 14, 2026 · 50.0km · 855m+
  • Dead Horse Ultra · Dead Horse 30KNovember 14, 2026 · 30.0km · 527m+
  • Dead Horse Ultra · Dead Horse 15KNovember 14, 2026 · 15.0km · 284m+
  • HOKA Pacific Trails California by UTMB · Pacific Trails 50KNovember 13, 2026 · 50.0km

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 States50-mile trail race calendar

Quad Rock 50mi · Race profile

Distance
81.0km
Gain
3060m+
FlatKM
104.9
Max
2157m
Min
1658m

About Quad Rock 50mi

Quad Rock 50mi is the 81.0km ultra trail at Quad Rock 2025 (Fort Collins, United States). The race starts on May 10, 2025.

Race strategy

Hold a steady pace and save energy for every section.

  • 503m 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 39.6km, 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–15.3km · Descent of 370m averaging 10%. 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. 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 · 15.3km–39.6km · Descent of 503m averaging 7%, high point 2159m, descent of 396m averaging 7%. 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.
  • Fade · 39.6km–71.0km · Climb of 502m. Plus 2 more climbs and 3 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. Your heart rate drifts down on its own: don't chase your early-race numbers, go by feel.
  • Home · 71.0km–79.5km · 8.5km 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 3060m+. With 38m/km of climbing, this is a rolling, mostly runnable course. By gradient, 42% of the distance is uphill, 41% downhill and 17% flat. The longest climb runs 8.2km at an average 5.5% grade (452m of vertical). The longest descent runs 6.9km at an average 7.3% grade (503m of vertical). The steepest climb averages 19.6% over 0.2km. The steepest descent drops at 20.1% over 0.2km. Surface: 98% trail. Flat-equivalent effort: 104.9 FlatKM.

Summits

The course also passes close to Arthurs Rock (2067m).

Poles

Poles bring little benefit here: only about 11.8km of pole-friendly terrain.

Quad damage

Quad damage risk is moderate (index 39 of 100), with 49% 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 39.6km, then run your race pace.
  • #2 · 11.4–15.2 km · 370 m D−, -9.7% · 64.3 km ahead → control
  • #1 · 20.7–27.6 km · 503 m D−, -7.3% · 51.9 km ahead → control
  • #3 · 33.6–39.6 km · 396 m D−, -6.6% · 39.9 km ahead → control
  • 47.7–51.4 km · 325 m D−, -8.9% · 28.1 km ahead → your pace
  • 67.8–71.0 km · 268 m D−, -8.5% · 8.5 km ahead → your pace
  • Plus 1 more notable descent not listed: your pace.

This page has a pacing and nutrition planner, a gradient matrix, an interactive elevation profile and historical weather for Quad Rock 50mi.

Other distances of Quad Rock 2025Quad Rock 25mi (40.0km)