Arc of Attrition - Arc 100M 2027
The forecast arrives five days before the start.
Here you'll find the elevation profile, an estimated finish time based on your UTMB Index and details of the 10 aid stations to plan your nutrition and hydration segment by segment.
What's your time based on your UTMB?
Times estimated by the RAVIT model, learned from real ultra-trail finish times. Enter your UTMB Index (utmb.world) to get a personalized estimate.
Cut-off times and crew - Arc of Attrition - Arc 100M · 2027
Data from the official race rules, checked for every edition. The race rules prevail. Positions are interpolated along the GPX track and are a guide, not official course marking.
What you'll find at each aid station
| Product | Lizard Pointkm 17.3 | Porthlevenkm 40.4 | Penzancekm 64.8 | Porthcurnokm 82.7 | Land's Endkm 90.3 | Pendeenkm 106.6 | Lelantkm 134.8 | Godrevykm 145.4 | Portreathkm 157.2 | Perranporth Airfieldkm 173.1 |
|---|---|---|---|---|---|---|---|---|---|---|
| Water | available | available | available | available | available | available | available | available | available | available |
| Hot meal | unavailable | available | available | unavailable | available | unavailable | available | unavailable | unavailable | available |
| Brand products · Näak | unavailable | unavailable | unavailable | unavailable | unavailable | available | unavailable | available | unavailable | unavailable |
La feuille de ton assistance pour Arc of Attrition - Arc 100M · 2027
Ton assistance peut te voir à ces postes. Ton plan RAVIT y met tes heures, ce qu'elle te tend et la route pour y aller.
Recto, verso et planche d'étiquettes, en PDF : l'exemple d'une coureuse de l'UTMB.
Elevation profile
The course and its aid stations
Arc of Attrition - Arc 100M: times, aid-station stops and fuelling needs by UTMB® Index
Between a UTMB® Index of 500 and 800, the estimated finish time on this race runs from 33h10 to 20h12, and the aid-station stop budget from 2h41 to 0h54. The longer the race, the more stops weigh: this is time you should plan to spend standing still, not only running.
Source
Below a UTMB® Index of roughly 430, the overall cut-off of 37h00 is no longer reachable at the estimated pace.
| UTMB® Index | Estimated time | Of which stops | Night hours | Carbs | Fluid | Sodium | Cut-off margin |
|---|---|---|---|---|---|---|---|
| 500 | 33h10 | 2h41 | 11.2 | 1,990 g | 23.2 L | 16,585 mg | +3h50 |
| 550 | 30h47 | 2h08 | 10 | 1,847 g | 21.6 L | 15,394 mg | +6h13 |
| 600 | 28h36 | 1h46 | 10 | 1,716 g | 20 L | 14,301 mg | +8h24 |
| 650 | 26h02 | 1h27 | 10 | 1,562 g | 18.2 L | 13,016 mg | +10h58 |
| 700 | 23h28 | 1h12 | 10 | 1,408 g | 16.4 L | 11,734 mg | +13h32 |
| 750 | 21h47 | 1h02 | 10 | 1,307 g | 15.3 L | 10,893 mg | +15h13 |
| 800 | 20h12 | 0h54 | 10 | 1,212 g | 14.1 L | 10,099 mg | +16h48 |
Figures based on 60 g of carbohydrate, 700 mL of fluid and 500 mg of sodium per hour, "average" preparation and mild conditions (15–25 °C). Above 25 °C, count on roughly 900 mL/h and 700 mg/h. Carbohydrate intake is trained: 60 g/h is a floor, 90 g/h assumes a glucose-fructose blend and a gut used to it.
Other trails worth preparing for
- North Coast 110170 km · 4,705 m D+ · November 7, 2026
- Slate Trail Ultra147 km · 3,666 m D+ · November 14, 2026
- Spine Challenger North242 km · 6,465 m D+ · January 10, 2027
- Ultra-Trail Snowdonia - Eryri 100M164 km · 9,356 m D+ · May 14, 2027
- Eryri by UTMB® - Eryri 100M®164 km · 9,356 m D+ · May 14, 2027
- Ultra-Trail Snowdonia - Eryri 100K107 km · 5,518 m D+ · May 15, 2027
- Eryri by UTMB® - Eryri 100K®108 km · 5,884 m D+ · May 15, 2027
- Centurion A100158 km · 1,087 m D+ · October 17, 2026
- UK Ultra South Downs 100 Mile162 km · 3,466 m D+ · October 3, 2026
Sources and method
- Time projection — times by UTMB Index are taken from the actual splits of runners in each level band on previous editions of this race, aid station stops included. No formula is used as long as these results exist.
- Trail nutrition — hourly targets for carbohydrate, fluid and sodium follow the commonly accepted ultra-endurance guidance. La Clinique du Coureur — Fuelling in trail running
- Course, aid stations and cut-offs — taken from the event's official rules, which prevail in case of any discrepancy. Official site — Arc of Attrition - Arc 100M
Weather for Arc of Attrition - Arc 100M
The weather for Arc of Attrition - Arc 100M will appear here as soon as the forecast models reach that date, around five days before the start: feels-like temperature, rain, snow, wind and storms, section by section and at your passage time.
Detailed weather for Arc of Attrition - Arc 100M, hour by hour on the courseFrequently asked questions
How many checkpoints?
Arc of Attrition - Arc 100M has 10 checkpoints: 7 aid stations and 3 water points. Details are in the two tables above.
What's the longest segment without aid?
The one leading to Lelant: 28.3 km and 979 m elevation gain. That's the one to load up for first.
How do I find the exact location of an aid station?
The Google Maps icon in the “Access” column opens the aid station's location: handy for planning your crew's routes.
What distance and elevation gain?
Arc of Attrition - Arc 100M is 173 km long with 5318 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 28h36 for Arc of Attrition - Arc 100M.
What's the weather forecast?
The weather for Arc of Attrition - Arc 100M will be published on this page around five days before the start, once the forecast models reach the race date. It will be detailed section by section: feels-like temperature, rain, snow, wind and storms.
Want to stack the odds in your favor for Arc of Attrition - Arc 100M?
In 2 minutes, RAVIT generates your complete plan: segment-by-segment time, carbs, water and sodium at every aid station, printable roadbook.
No card required · Instant results