How far is the Arc 100K?

The Arc 100K is one distance: 100K (62.1 miles).

How much climbing is in the Arc 100K?

The 100K has 2,402 m of ascent.

How hard is the Arc 100K?

100K: Expert. TRP grades come from distance and climb measured off the course file, not from the organiser.

Is the Arc 100K course marked?

No. The Arc 100K is not a marked course. You are expected to navigate it yourself.

What are the cut-offs for the Arc 100K?

Overall time limits — 100K: 16h.

Can I download the Arc 100K route?

Yes. The GPX for each distance is free to download here, with no sign-up, the same as every route on Trail Running Planet.

When is the next Arc 100K?

Sat, 23 Jan 2027, 10:00. Entries open.

Arc of Attrition by UTMB Arc 100K

Land's End, CornwallSat, 23 Jan 2027

Land's End to Perranporth Airfield on the wildest of the Atlantic coast.

100K

62 miles

2,402 m ascent

24 m per km

16h cut-off

9:36/km to make it

coastalcliffNavigation required

Nobody has reviewed this one yet

No reviews of the Arc 100K, and nothing on what people wore. Both are things no organiser publishes and every runner wants before they enter — how it actually went, and what was on your feet.

Ran it? Write the first review

Running it soon? Connect Strava and we will ask you about it the day you finish, so you do not have to remember to come back.

The course

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EXPERT

TRP grade · E5·T3

16h cut-off, which needs 9:36/km

6 checkpoints

Download GPXFree, no sign-up.

This file is from a previous running and the course may have changed since. If you are navigating with it, get the current version from Arc of Attrition by UTMB first.

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How to enter

Sat, 23 Jan 2027 · Entries open

Enter via UTMB World Series ↗

Entries are handled by UTMB World Series, not by us. We take nothing for sending you there.

Add to your calendar · with the start time

Common questions

: The Arc 100K is one distance: 100K (62.1 miles).
: The 100K has 2,402 m of ascent.
: 100K: Expert. TRP grades come from distance and climb measured off the course file, not from the organiser.
: No. The Arc 100K is not a marked course. You are expected to navigate it yourself.
: We don't hold a compulsory kit list for the Arc 100K. Arc of Attrition by UTMB confirm mandatory kit in their race information, usually in the final instructions.
: Overall time limits — 100K: 16h.
: We don't hold a checkpoint list for the Arc 100K. What's on the table varies a lot between races, so check the Arc of Attrition by UTMB race information rather than turning up expecting food.
: Yes. The GPX for each distance is free to download here, with no sign-up, the same as every route on Trail Running Planet.
: Sat, 23 Jan 2027, 10:00. Entries open.