Bossière - 20km 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 - Bossière - 20km · 2026
| Aid station | Cum. km | Cum. D+ | Seg. km | Seg. D+ | Seg. D- | Crew | Cut-off | Access |
|---|---|---|---|---|---|---|---|---|
| Arrivée | 19.9 | 289 m | 19.9 | 289 m | 284 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.
La feuille de ton assistance pour Bossière - 20km · 2026
Les règles d'assistance de cette course ne sont pas encore connues : tu marqueras tes rendez-vous toi-même.
Recto, verso et planche d'étiquettes, en PDF : l'exemple d'une coureuse de l'UTMB.
Elevation profile
The course and its aid stations
Bossière - 20km: 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 2h01 to 1h21, and the aid-station stop budget from 0h02 to 0h01. 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 | 2h01 | 0h02 | — | 121 g | 1.4 L | 1,008 mg |
| 550 | 1h51 | 0h02 | — | 111 g | 1.3 L | 928 mg |
| 600 | 1h44 | 0h02 | — | 104 g | 1.2 L | 865 mg |
| 650 | 1h37 | 0h01 | — | 97 g | 1.1 L | 809 mg |
| 700 | 1h31 | 0h01 | — | 91 g | 1.1 L | 759 mg |
| 750 | 1h26 | 0h01 | — | 86 g | 1 L | 715 mg |
| 800 | 1h21 | 0h01 | — | 81 g | 0.9 L | 671 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
- Burdinne - 12km-night13 km · 330 m D+ · November 13, 2026
- Burdinne - 23km-night23 km · 526 m D+ · November 13, 2026
- Heusden-Zolder - 17km17 km · 217 m D+ · November 15, 2026
- Heusden-Zolder - 21km21 km · 230 m D+ · November 15, 2026
- Kasterlee - Halve Natuurmarathon21 km · 100 m D+ · November 15, 2026
- Ghlin (Mons) - Trail du Dragon18 km · 148 m D+ · November 15, 2026
- Knokke-Heist - 17km17 km · 133 m D+ · November 22, 2026
- Vissenaken - 29km29 km · 229 m D+ · November 22, 2026
- Knokke-Heist - 25km24 km · 122 m D+ · November 22, 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 — Bossière - 20km
Weather for Bossière - 20km
The weather for Bossière - 20km 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 Bossière - 20km, hour by hour on the courseFrequently asked questions
How many checkpoints?
Bossière - 20km has 1 checkpoint: 1 checkpoint with undocumented contents. Details are in the two tables above.
What distance and elevation gain?
Bossière - 20km is 20 km long with 289 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 1h44 for Bossière - 20km.
What's the weather forecast?
The weather for Bossière - 20km 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 Bossière - 20km?
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