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Trail Running · Réunion

🇷🇪Diagonale des Fous:
Course Analysis & Race Readiness

174 km with 9,981 m of climbing and 9,935 m of descent across 26 climbs and 19 descents. From near sea level to 2,486 m, this course punishes legs that can't absorb relentless downhill.

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

174 km
Distance
+9,900 m
Vertical Gain
−9,860 m
Total Descent
Oct 15, 2026
Next Edition · 85 days out
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The Course · GPS-Measured

What 174 km / 108 mi and 9,900 m / 32,480 ft of vertical gain actually look like

Measured from the GPS track: 174 km / 108 mi and 9,900 m / 32,480 ft of vertical gain. This is the terrain you're signing up for: read it before it reads you.

Course Profile

Terrain summary
Claimed vs GPS-Measured
Claimed · Organizer
174km
Distance
+9,980m
Gain
−0.0 km−80 m
GPS-Measured
174km
Distance
+9,900m
Gain
Climb & Gradient
+9,900 mTotal Gain
−9,860 mTotal Loss
Gradient Distribution
23%
Flat
≤3% grade
27%
Run-Climb
3–15% up
12%
Steep Climb
>15% up
38%
Descent
downhill
Steepest Sustained Sections
1
Descent
KM 67.3–71.5 · −1,127 m
-26.7%
2
Climb
KM 115.0–120.0 · +1,118 m
+22.1%
3
Descent
KM 106.0–108.0 · −588 m
-20.3%
4
Climb
KM 111.0–114.0 · +653 m
+19.6%
Finish & Cutoff Times

What it takes to finish

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

23h 32m
Winning time
25h 36m
Top 5
28h 49m
Top 10
48h 00m
Median finisher
66h 00m
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 output across 174 km from 3 m to 2,486 m elevation.
ClimbingVertical power
21%
26 climbs totaling 9,981 m, including a 1,129 m ascent and pitches over 22%.
DescendingEccentric / braking
48%
44% of the course runs downhill: 9,935 m of loss, including an 1,919 m descent.
DurabilityLate-race resilience
31%
Repeated 2,000 m+ swings and late steep climbs test resilience deep into the distance.
The Profile in One Line

An ultra-distance course where descending dominates: 44% downhill against 9,935 m of loss over 174 km.

Aerobic FoundationalClimbing 21%Descending 48%Durability 31%

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
49
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
68
At 174 km, steady aerobic output must persist across the full elevation range from 3 m to 2,486 m. Managing effort over this duration underpins everything else.
Climbing
83
With 26 climbs and 9,981 m of gain, the terrain demands repeated ascending, including a 1,129 m climb and sustained pitches exceeding 20%. Very-steep-climb grades cover 21.4% of the course.
Descending
21
Descending is the defining demand: 44% downhill, 9,935 m of loss over 19 descents, with very-steep-descent grades on 21.5% of the course and a single 1,919 m drop. Legs must brake continuously without breaking down.
Durability
69
Total vertical near 20,000 m across 174 km, with a 1,118 m climb past 114 km, forces the body to hold form as fatigue accumulates late in the race.
km 67–72
Steepest Plunge
A 1,127 m descent at -26.7% over roughly 4 km hammers the quads early, setting up the durability challenge for the second half.
km 111–120
Late Vertical Wall
Back-to-back climbs gaining 653 m at 19.6% then 1,118 m at 22.1% demand strong ascending legs well past the 110 km mark.
Descent load
Relentless Downhill
With 9,935 m of loss and the biggest single descent at 1,919 m, sustained eccentric braking is the course's central test of the legs.
That was a sample

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