Arc of Attrition - Arc 100K 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 5 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 100K · 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 | Pendeenkm 16.2 | Lelantkm 44.5 | Godrevykm 55.0 | Portreathkm 66.9 | Perranporth Airfieldkm 82.8 |
|---|---|---|---|---|---|
| Water | available | available | available | available | available |
| Brand products · Näak | available | unavailable | available | unavailable | unavailable |
| Hot meal | unavailable | available | unavailable | unavailable | available |
La feuille de ton assistance pour Arc of Attrition - Arc 100K · 2027
L'assistance n'est autorisée sur aucun poste de cette course.
Elevation profile
The course and its aid stations
Arc of Attrition - Arc 100K: 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 13h46 to 8h27, and the aid-station stop budget from 0h47 to 0h17. 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 405, the overall cut-off of 16h00 is no longer reachable at the estimated pace.
| UTMB® Index | Estimated time | Of which stops | Night hours | Carbs | Fluid | Sodium | Cut-off margin |
|---|---|---|---|---|---|---|---|
| 500 | 13h46 | 0h47 | 2.8 | 826 g | 9.6 L | 6,880 mg | +2h14 |
| 550 | 12h44 | 0h39 | 1.7 | 764 g | 8.9 L | 6,369 mg | +3h16 |
| 600 | 11h47 | 0h33 | 0.8 | 707 g | 8.2 L | 5,892 mg | +4h13 |
| 650 | 10h42 | 0h28 | — | 642 g | 7.5 L | 5,348 mg | +5h18 |
| 700 | 9h53 | 0h23 | — | 593 g | 6.9 L | 4,938 mg | +6h07 |
| 750 | 9h05 | 0h20 | — | 545 g | 6.4 L | 4,541 mg | +6h55 |
| 800 | 8h27 | 0h17 | — | 507 g | 5.9 L | 4,224 mg | +7h33 |
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
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- South Downs Way 50M79 km · 1,754 m D+ · April 10, 2027
- Granite Peaks Ultra 50k52 km · 3,896 m D+ · April 17, 2027
- Ultra-Trail Snowdonia - Eryri 80K79 km · 2,547 m D+ · May 14, 2027
- Eryri by UTMB® - Eryri 80K®79 km · 2,547 m D+ · May 14, 2027
- Eryri by UTMB® - Eryri 50K®58 km · 3,407 m D+ · May 15, 2027
- Ultra-Trail Snowdonia - Eryri 50K58 km · 3,407 m D+ · May 15, 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
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 100K
Weather for Arc of Attrition - Arc 100K
The weather for Arc of Attrition - Arc 100K 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 100K, hour by hour on the courseFrequently asked questions
How many checkpoints?
Arc of Attrition - Arc 100K has 5 checkpoints: 4 aid stations and 1 water point. Details are in the two tables above.
What's the longest segment without aid?
The one leading to Lelant: 28.3 km and 981 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 100K is 83 km long with 2588 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 11h47 for Arc of Attrition - Arc 100K.
What's the weather forecast?
The weather for Arc of Attrition - Arc 100K 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 100K?
In 2 minutes, RAVIT generates your complete plan: segment-by-segment time, carbs, water and sodium at every aid station, printable roadbook.
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