Trail Running · Chamonix

🇫🇷UTMB:
Course Analysis & Race Readiness

174km with 9,977m of gain and 9,978m of loss across 22 climbs and 16 descents. A relentless mountain loop where sustained climbing and punishing descents accumulate over an ultra-length day.

CourseRecon scores your own training against the descending and durability demands that define UTMB — the sample analysis below shows exactly how.

174 km

Distance

+9,980 m

Vertical Gain

−9,980 m

Total Descent

Aug 28, 2026

Next Edition · 39 days out

Organizer lists +9,900 m of climbing. We measured +9,980 m from the GPS track — +80 m more than advertised.

Check YOUR readiness

Connect Strava · No card · 2 min

The Course · GPS-Measured

What 174 km / 108 mi and 9,980 m / 32,730 ft of vertical gain actually look like

Measured from the GPS track: 174 km / 108 mi and 9,980 m / 32,730 ft of vertical gain. This is the terrain you're signing up for: read it before it reads you.

Course Profile

Segments

Daylight

Terrain summary

Claimed vs GPS-Measured

Claimed · Organizer

174km

Distance

+9,900m

Gain

+0.4 km+80 m

GPS-Measured

174km

Distance

+9,980m

Gain

The organizer's flyer undersells this course by +80 m of climbing and +0.4 km.

Climb & Gradient

+9,980 mTotal Gain

−9,980 mTotal Loss

Gradient Distribution

25%

Flat

≤3% grade

25%

Run-Climb

3–15% up

13%

Steep Climb

>15% up

37%

Descent

downhill

Steepest Sustained Sections

Climb

KM 70.3–72.9 · +474 m

+18%

Descent

KM 46.2–51.6 · −946 m

-17.6%

Climb

KM 100.0–105.0 · +767 m

+17.5%

Climb

KM 145.0–150.0 · +763 m

+17.2%

Finish & Cutoff Times

What it takes to finish

Reference finish times from past results — use them to set a realistic goal pace.

19h 19m

Winning time

20h 20m

Top 5

21h 20m

Top 10

40h 48m

Median finisher

46h 04m

Back of pack

What This Race Demands

Four things this course asks of your body

Every course weights the four pillars of mountain-ultra fitness differently. Descending carries 48% of the scoring weight on this course — the terrain makes that the deciding factor.

Weighting shows where readiness is won or lost at this distance — not whether you need each pillar. An aerobic base is a given for a race this long, so it carries little deciding weight even though it's essential — the gaps open on the climbs, descents and the back half.

AerobicSustained engine

Foundational

Sustained effort across 174km and well over a full day of continuous movement.

ClimbingVertical power

20%

22 climbs totaling 9,977m, including a 1,306m ascent and a 10.8km sustained pull.

DescendingEccentric / braking

48%

9,978m of loss across 16 descents, including a 14.6km descent and a 1,257m drop.

DurabilityLate-race resilience

32%

Repeated climb-descent cycles from 1,043m to a 2,562m high point over 174km.

The Profile in One Line

An ultra-distance loop balancing 22 climbs against 16 descents, with descending the dominant demand over relentless vertical.

Aerobic FoundationalClimbing 20%Descending 48%Durability 32%

Here's how CourseRecon reads a course and an athlete

Sample Readiness Analysis

What a readiness result looks like for this course

This is a worked example for a representative strong mountain-ultra athlete — not your score. Connect your own training and the same analysis runs on you.

Sample

OUT OF 100

QUESTIONABLE

For a representative strong mountain-ultra athlete

This is a sample — connect your Strava to see your own result.

Pillar Breakdown

Aerobic

The 174km distance and multi-day duration demand a deep aerobic base capable of steady output for many hours without decisive high-intensity sections.

Climbing

22 climbs stacking 9,977m of gain, including a 1,306m ascent and grades reaching 18%, require both power on steep pitches and endurance on the 10.8km longest climb.

Descending

With 9,978m of loss over 16 descents and pitches steeper than -17%, quad-shredding downhills like the 14.6km descent and the 946m drop dominate the course's demands.

Durability

Elevation swings between 1,043m and 2,562m across 22 climbs and 16 descents mean legs must absorb repeated vertical loading late into the effort.

KM46-52

The 946m Plunge

A 5.4km descent losing 946m at -17.6% pounds the quads early, setting up long-term durability costs. Riding the brakes here mortgages the second half.

KM100-105

Late Steep Ascent

A 767m climb at 17.5% grade past the 100km mark tests climbing power on already-fatigued legs. Steep pitches this deep into the race separate the field.

KM145-150

Final Vertical Test

A 763m climb at 17.2% near km 145 arrives after 140-plus kilometers, demanding durability to keep grinding uphill when reserves are nearly gone.

That was a sample