Groix - trail des marathonniers grande boucle 2026
The forecast arrives five days before the start.
Here you'll find the elevation profile and an estimated finish time based on your UTMB Index.
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 - Groix - trail des marathonniers grande boucle · 2026
| Aid station | Cum. km | Cum. D+ | Seg. km | Seg. D+ | Seg. D- | Crew | Cut-off | Access |
|---|---|---|---|---|---|---|---|---|
| Arrivée | 27.4 | 617 m | 27.4 | 617 m | 610 m | — | — | — |
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
Aid station contents not documented.
Elevation profile
The course and its aid stations
Groix - trail des marathonniers grande boucle: 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 2h52 to 2h04, and the aid-station stop budget from 0h03 to 0h02. The longer the race, the more stops weigh: this is time you should plan to spend standing still, not only running.
Source
| UTMB® Index | Estimated time | Of which stops | Night hours | Carbs | Fluid | Sodium |
|---|---|---|---|---|---|---|
| 500 | 2h52 | 0h03 | — | 172 g | 2 L | 1,434 mg |
| 550 | 2h42 | 0h03 | — | 162 g | 1.9 L | 1,349 mg |
| 600 | 2h32 | 0h02 | — | 152 g | 1.8 L | 1,265 mg |
| 650 | 2h24 | 0h02 | — | 144 g | 1.7 L | 1,202 mg |
| 700 | 2h17 | 0h02 | — | 137 g | 1.6 L | 1,145 mg |
| 750 | 2h11 | 0h02 | — | 131 g | 1.5 L | 1,089 mg |
| 800 | 2h04 | 0h02 | — | 124 g | 1.5 L | 1,036 mg |
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
- Pierre Buffière - La TimGroup41 km · 1,331 m D+ · October 18, 2026
- Montégut - La Chevauchée de D’Artagnan28 km · 761 m D+ · October 18, 2026
- Arette - De Soum en Soum (Duo)25 km · 1,350 m D+ · October 18, 2026
- Bazoges-en-Paillers - 24km24 km · 378 m D+ · October 18, 2026
- Sainte-Ruffine - 19km19 km · 530 m D+ · October 18, 2026
- Corte - U PERIPLU DI CORTI Solo21 km · 1,931 m D+ · October 18, 2026
- Pierre Buffière - La Delta Industrie24 km · 783 m D+ · October 18, 2026
- Falicon - Trail de la Grande Ratapignata - Solo20 km · 1,275 m D+ · October 18, 2026
- Céret - Trail des Salines24 km · 1,535 m D+ · October 18, 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 — Groix - trail des marathonniers grande boucle
Weather for Groix - trail des marathonniers grande boucle
The weather for Groix - trail des marathonniers grande boucle 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 Groix - trail des marathonniers grande boucle, hour by hour on the courseFrequently asked questions
How many checkpoints?
Groix - trail des marathonniers grande boucle has 1 checkpoint: 1 checkpoint with undocumented contents. Details are in the two tables above.
What distance and elevation gain?
Groix - trail des marathonniers grande boucle is 27 km long with 617 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 2h32 for Groix - trail des marathonniers grande boucle.
What's the weather forecast?
The weather for Groix - trail des marathonniers grande boucle 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 Groix - trail des marathonniers grande boucle?
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