Loading Race For You
Loading page content.
entries openArc of Attrition by UTMB
Arc 100K
Arc of Attrition by UTMB
Next edition: Saturday, 23 January 2027Land's End to Perranporth, England
A technical winter ultra from Land's End to Perranporth on the South West Coast Path, compressing rugged cliffs, 2,708m of ascent and long self-sufficient stretches into a 16-hour race window.
Official race site (opens in a new tab)
Optional device-only history; never synced to your account. Shared-device users can leave it off.
Distance51.4 mi
Ascent2,708m
Climb / km32.7m
Cutoff16h
Cutoff pace11:37/km
Technicality8.1/10
EntryNot verified
FormatPoint-to-point
Next edition
23 January 2027
This is the most relevant confirmed edition currently held for the permanent race family. Edition-specific facts should still be checked against the final organiser instructions.
Edition archive
This is the only edition currently stored for this race family. Earlier verified editions can be added without changing the permanent race URL.
Check the official race source (opens in a new tab)Race For You difficulty
5.3/ 10
Hard
High evidence confidence · 94% evidence coverage
This score is driven most by technical terrain, exposure and self-sufficiency. Difficulty V2's separate time-limit modifier adds 0.35 points here and is capped at 0.70; a broad limit cannot erase extreme intrinsic demand. This is independent of the public Cutoff Pressure V2 band.
Weather, conditions and individual preparation can change the real difficulty significantly.
How the score works Distance, weighted 30 percent4.1 out of 10
Climbing, weighted 25 percent5.1 out of 10
Technicality, weighted 15 percent8.1 out of 10
Accumulated burden, weighted 17 percent2.5 out of 10
Exposure & support, weighted 13 percent6.3 out of 10
Course analysis
What shapes this race
Expect sections where foot placement and downhill confidence matter.
trailcoastaltechnical
Climbing density
32.7m per km
A more useful comparison than total ascent alone: it shows how consistently the course asks you to climb.
Cutoff analysis
Very high pressure
To finish inside 16h, the raw average required is 11:37 per kilometre (18:41 per mile), including every stop.
Raw pace11:37/km
PressureVery high pressure
Cutoff pressure compares the published time limit with distance, ascent and verified course demands. Lower pressure does not mean the race is easy. Raw pace includes checkpoints, food stops, navigation errors and any sleep; it is not a pacing plan.
Who this suits
First ultra?
This is not designed as a first-ultra recommendation. Significant endurance, navigation or mountain-race experience is strongly advised.
2.9/10 suitability
Navigation
partially marked
Do not assume closed-road-race levels of signage. Know the organiser’s navigation requirements and keep the official route available.
Exposure & kit
extensive kit
Some entrants may run into darkness depending on pace and start time. Prepare lighting even if your best-case plan finishes earlier.
Personal race predictor
Will you make the cutoff?
Use a previous result to estimate a realistic range for Arc 100K, your potential buffer and the biggest change in demand.
Practical detail
Support & logistics
StartLand's End
FinishPerranporth
Support levelsemi-supported
LogisticsAccommodation nearby
LogisticsBag drop
UTMB100K
Logistics are only shown where currently recorded. Confirm parking, transport, crew access and final aid-station plans with the organiser.
Latest verification
Trust the source, see the gaps.
Data PartialThe 2027 date, 82.7km distance, 2,708m ascent and 16-hour maximum time are verified on the official race page. Price, field size and exact aid-station count remain unknown.
- Successful source check
- 1 Sept 2026
- Catalogue record updated
- 1 Sept 2026
- Official source
- Available
Still unverified: entry price.
Event details can change after a successful source check. Confirm the final route, kit, cutoff, price and entry terms directly with the organiser before entering or travelling.
Found something wrong?
Help keep this race accurate.
Wrong cutoff? Date changed? New course? Tell us what moved and include the official source if you have it.
Report an updateKeep exploring
Browse the race catalogue
Use explicit distance, place, date, terrain and format filters to compare current races.