ExtremeAugust

Ultra-Trail du Mont-Blanc (UTMB)

Chamonix, France

106 miles

The most prestigious ultra in the world, UTMB circles Mont Blanc through France, Italy, and Switzerland. Legendary for brutal elevation, unpredictable alpine weather, and an electric atmosphere.

Race Overview

Distance

106 miles

Cutoff Time

46 hours 30 minutes

Finish Rate

60-70%

Entrants

~2300

Terrain

Trail

Month

August

Terrain

Alpine trails, technical mountain passes, exposed ridges, and rocky descents across three countries

Entry Method

Running Stones points system + lottery

Elevation Profile

Start: 3,400ft

High: 8,668ft

Elevation Gain

32,800 feet

Elevation Loss

32,800 feet

High Point

8,668ft

Low Point

3,400ft

Elevation Range: 5,268 feet

Key Course Sections

Chamonix to Les Contamines

Moderate

Miles 0-20 • +5,900 / -4,900 feet

Starting in the chaos of Chamonix, runners climb to Col de Voza before descending to Les Contamines.

Les Contamines to Courmayeur

Extreme

Miles 20-50 • +13,100 / -13,100 feet

The toughest section with multiple high alpine passes including Col de la Seigne entering Italy.

Courmayeur to Champex-Lac

Extreme

Miles 50-75 • +8,200 / -8,900 feet

Grand Col Ferret into Switzerland, entering the second night with accumulated fatigue.

Champex-Lac to Vallorcine

Hard

Miles 75-92 • +4,900 / -5,200 feet

La Giète climb tests remaining strength. Technical descents require focus despite exhaustion.

Vallorcine to Chamonix

Hard

Miles 92-106 • +3,600 / -4,600 feet

Final climb to La Flégère, then triumphant descent into Chamonix for finish line celebration.

Recommended Pacing Strategy

UTMB is a mountaineering challenge as much as a running race. Most of the race is power hiking steep climbs and controlled descents. Ego has no place here—hike everything over 10% grade and save running for the valleys.

Key Pacing Tips

Expect to hike 50-60% of the race - plan for it
Weather changes rapidly - carry all required gear
Night navigation is critical - practice with your headlamp
Aid stations are well-stocked but crowded - be patient
The crowds in Chamonix will make you start too fast - resist

Get Your Personalized Pacing Plan

Upload the Ultra-Trail du Mont-Blanc (UTMB) GPX file and receive a segment-by-segment pacing strategy tailored to your goal time, optimized for every climb and descent.

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