Trail Running · Chamonix

🇫🇷OCC:
Course Analysis & Race Readiness

Sixty kilometers with 3,257m of gain and 3,129m of loss across seven climbs and seven descents. Downhill dominates 40% of the course, with a steep 820m climb defining the midsection.

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

60.4 km

Distance

+3,240 m

Vertical Gain

−3,110 m

Total Descent

27 Aug 2026

Last Edition · Past

Check YOUR readiness

Connect Strava · No card · 2 min

The Course · GPS-Measured

What 60.4 km / 37.5 mi and 3,240 m / 10,620 ft of vertical gain actually look like

Measured from the GPS track: 60.4 km / 37.5 mi and 3,240 m / 10,620 ft of vertical gain. This is the terrain you're signing up for: read it before it reads you.

Course Profile

Claimed vs GPS-Measured

Claimed · Organizer

60.4km

Distance

+3,260m

Gain

−0.0 km−20 m

GPS-Measured

60.4km

Distance

+3,240m

Gain

Climb & Gradient

+3,240 mTotal Gain

−3,110 mTotal Loss

Gradient Distribution

25%

Flat

≤3% grade

26%

Run-Climb

3–15% up

12%

Steep Climb

>15% up

37%

Descent

downhill

Steepest Sustained Sections

Descent

KM 42.6–46.0 · −586 m

-17.2%

ClimbCRUX

KM 25.1–30.4 · +820 m

+15.8%

Climb

KM 13.9–18.5 · +674 m

+14.7%

Descent

KM 18.5–24.4 · −744 m

-12.7%

Finish & Cutoff Times

What it takes to finish

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

5h 12m

Winning time

5h 27m

Top 5

5h 31m

Top 10

14h 30m

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 49% 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 output across 60km with 3,257m of climbing and repeated hard efforts.

ClimbingVertical power

23%

Seven climbs including an 820m ascent at 15.8% and a 674m pitch at 14.7%.

DescendingEccentric / braking

49%

Forty percent downhill; a 744m loss and a 586m drop at -17.2% test the legs.

DurabilityLate-race resilience

29%

Seven up-and-down cycles over 60km demand resilience deep into the closing kilometers.

The Profile in One Line

A descent-heavy 60km with sharp, sustained climbs and constant elevation change from 914m to a 2,293m high point.

Aerobic FoundationalClimbing 23%Descending 49%Durability 29%

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

READY

For a representative strong mountain-ultra athlete

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

Pillar Breakdown

Aerobic

100

The 60km distance and 3,257m of total gain require a strong sustained engine, with efforts stacked across seven climbs and long descents.

Climbing

With 28% of the course above 10% grade and 820m and 674m climbs at steep pitches, climbing power is decisive in the middle third.

Descending

Descending carries the largest share of the demand at 40% downhill, including a 744m loss and a -17.2% grade over 586m that punish quads.

Durability

Seven climb-descent cycles and 3,129m of cumulative loss erode the legs, so late-race steep descents test whoever still has control.

km 25.1–30.4

The 820m Signature Climb

The course's biggest climb gains 820m over roughly 5km at 15.8%, arriving mid-race and demanding sustained climbing strength before the descents that follow.

km 42.6–46.0

Steepest Descent Late

A 586m drop at -17.2% comes deep in the race, testing quad durability and descending control on tired legs.

km 18.5–24.4

The 744m Plunge

The largest single descent loses 744m at -12.7% over nearly 6km, an early quad-loading effort that shapes the rest of the day.

That was a sample