Trail guide · Chamonix, France
UTMB 2027 training guide: course, kit and preparation
A loop of the Mont-Blanc massif through France, Italy and Switzerland: 174 km and 9,700 m of climbing in 2026, with 45h30 to finish. Most of it is hiked, much of it at night, and the weather can go from 30 °C to snow.
OpenAthlete is not affiliated with the organisers. This is an independent preparation guide.
Key facts
2027
- Date
- 2027 date not announced yetUsually the last week of August (24–30 August in 2026). The press reports the week may move in 2027 because of the road cycling World Championships in Haute-Savoie.
- Start
- Friday 19:45 from Chamonix in 2026
- Distance
- 174 km
- Elevation
- +9,700 m
- Time limit
- 45h30 (2026)
- Course
- A loop around the Mont-Blanc massif from and to Chamonix, through France, Italy and Switzerland: mountain trails, cols above 2,000 m, technical descents. Shorter races of the week: CCC (108 km, 6,200 m) and OCC (60 km, 3,500 m).
- Usual weather
- August in Chamonix: 9 to 23 °C on average (Météo-France normals). The organisers warn of 30 °C in the valleys and down to −10 °C felt above 2,000 m, with rain, hail or snow.
Facts checked on 4 November 2026. Organisers change things: confirm on the official site before you book anything.
The course, seen by a coach
UTMB: what it asks of you, and how to train for it
9,700 m, mostly on foot
The climbs are long, and almost everyone hikes them. Your uphill walking speed decides your finish time more than your flat pace. From six months out, one session a week of 30 to 60 min steep hiking with poles, and long days in the mountains where you climb 2,000 m or more.
One night for sure, two for most
With an evening start, everyone runs the first night and most finishers see a second one. Plan where you would take a 10 to 20 minute nap if you need it, and try a short nap once in training, on a long night outing, to know how you wake up from it.
Train with the full mandatory kit
The organisers publish a mandatory equipment list and can add a cold-weather kit when the forecast demands it. Carry the full pack, cold kit included, on every long day from May, so the weight and the fit are no surprise in August.
Training plan
No ready-made plan for UTMB, honestly
Our trail plans stop at 50 km. Past that, a generic plan for 174 km would be guesswork: your past races, your terrain at home and your weeks matter more than any template. Use the 50 km plan as a stepping stone the season before, then build the long block with a coach or in your own calendar.
The race in km-effort
271km-effort
- UTMB174 km · +9,700 m
- Our 50 km plan race50 km · +2,500 m
- Road marathon42.2 km · 0 m
174 km + 9,700 m ÷ 100 = 271 km-effort, 3.6 times the race our 50 km plan prepares. Enter 174 km and 9,700 m in the trail time estimator with a recent race to get a finish window.
What the preparation must include
Four things no long trail forgives you for skipping
Back-to-back long days
Four to six weekends before the taper, run long on Saturday and again on Sunday on tired legs: 4 h then 3 h, on terrain like the race. It teaches the legs and the stomach to keep going without one 8-hour run that wrecks a week.
Night running
Run with your race headlamp at least three or four times, on trails, after dark. Footing is slower, sleepiness hits around 3 am, and you want to know your battery life before the race tells you.
Poles and power hiking
On long climbs, most runners walk. Train it: 20 to 40 min of steep uphill hiking with poles, once a week. If poles are allowed and you plan to use them, never race with them for the first time.
Descents
Quads fail on the way down, not up. Run long downhills every week from three months out, add step-downs and lunges, and practise technical ground at an easy pace until it feels boring.
Build the block in OpenAthlete: plan the back-to-back weekends in the calendar, write the hill sessions once, and send them to your Garmin, COROS or Suunto watch.
Plan it for freeUTMB: questions runners ask
Through a lottery weighted by Running Stones, earned at UTMB World Series events (at least one within the two years before the lottery), plus a valid UTMB Index in the 100K or 100M category. Pre-registration is usually in December and the lottery in January. Rules can change: check the official site.
The dates were not announced on 4 November 2026. The race usually takes place in the last week of August, but the press reports it may have to move in 2027 because of the road cycling World Championships in Haute-Savoie (24 August to 5 September 2027).
Count six to nine months of specific work on top of a solid trail base, and at least one long race (50 km or more) the season before. The last 12 to 16 weeks carry the big weekends and the night runs; the last two or three weeks are a taper.
No. OpenAthlete is not affiliated with the organisers of UTMB. This is an independent preparation guide written from the official information available on 4 November 2026. Registration, rules and the final course are on the official site.
Prepare UTMB with the plan on your watch
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