How to Train for UTMB: A Coach's 24-Week Framework for 174 km

Getting a UTMB bib takes years of Running Stones and a lottery. Getting to the finish in Chamonix takes about six months of the most specific training you will ever do. This is the framework I use for it, written for the mid-pack: a runner with at least one 100K mountain finish, targeting somewhere between 32 and 44 hours.

Course details shift slightly from year to year. The numbers below are the official 2026 edition; check the official UTMB page for the current course, cutoffs, and mandatory kit before you build around them.

What the UTMB actually demands

• Distance and climb. 174 km and 9,700 m of elevation gain in 2026, about 56 m per kilometre, with the same amount of descent because it is a loop. Ten major climbs of 700-1,500 m spread across France, Italy, and Switzerland: Col du Bonhomme (about 2,330 m), Col de la Seigne (about 2,520 m), the Grand Col Ferret (about 2,540 m), and a series of 700-900 m ascents through Champex-Lac, Bovine, Catogne, and the final climb toward La Flégère.
• The start. Friday at 19:45 in Chamonix. You run the first 30 km in the dark, over Col de Voza toward Les Contamines, in a field of more than two thousand people. The first serious climb, to Col du Bonhomme, is done around midnight.
• Two nights. With a 45-hour-30 limit and a mid-pack finish of 35-42 hours, most runners see the first night from the start, the whole of Saturday, the second night between roughly Courmayeur or Champex-Lac and Vallorcine, and finish on Sunday. The second night is where UTMB races end: not from injury, but from a mind that has been awake for 40 hours deciding it has had enough.
• Courmayeur, around 80 km. The mid-point, a large aid station with drop bags, and the single most common place to quit. Runners who arrive there with a plan for the next 30 minutes continue; runners who arrive there to "see how they feel" often do not.
• Cutoffs. They are generous at the start and tighten in Switzerland. The runners who miss them are almost always the ones who lost hours to stomach, feet, or sleep, not the ones who were slow on the climbs.

Who this framework is for

Honestly stated: you should have finished at least one 100 km mountain race with over 5,000 m of gain, and ideally something with a night in it, before you build toward UTMB. If you are between a 100K and a 100-miler, the first ultra distance guide walks through what changes. The framework assumes a base of 60-80 km per week with 1,500 m or more of weekly vertical, held for at least two months.

The 24-week structure

Six blocks of four weeks, each built as three loading weeks and one recovery week. The recovery weeks are the reason the peak block exists at all; the runners who skip them do not get a peak block, they get an injury.

These are numbers for a 35-42 hour finisher. A sub-30-hour target needs more speed rather than more volume; a finish-inside-the-cutoff target can drop the kilometres by 20% but should keep every long day and every night session.

Base: weeks 1-4

Five runs a week, 80% easy, and the two things that never leave the plan from here: a weekly strength session built on single-leg and eccentric work, and a weekly steep hike of 60-90 minutes with poles. On UTMB you will hike for something like 20 hours. Hiking economy is not a footnote; it is the most trainable variable in the whole race.

Build 1: weeks 5-8

Back-to-back long runs start on alternate weekends: 4-5 hours on Saturday, 2-3 on Sunday, with the Sunday run's purpose being to run on the quads Saturday emptied. A dedicated downhill session goes in weekly - 5-8 repeats of a 200-300 m technical descent - and the long runs start carrying 1,500 m or more of gain on terrain that looks like the race. If your terrain is flat, the vertical gain guide covers how to build mountain legs without mountains, and it does work, but budget a race-week reconnaissance day in the Alps if you possibly can.

Build 2: weeks 9-12

Long days reach 5-7 hours, and the first night session arrives: a run that starts at 21:00 and finishes after 01:00, ideally as the second half of a long day. Gut training becomes deliberate in this block: every run over three hours is a rehearsal of race intake at 60-90 g of carbohydrate per hour, with the specific foods you plan to use and the specific foods the aid stations serve. Keep one moderate session a week - long hill repeats of 5-8 minutes, or a rolling tempo - to protect economy while the volume climbs.

Peak 1: weeks 13-16

The rehearsal race sits here: a 100 km mountain race with 5,000 m or more of gain, 8-10 weeks before UTMB, run at UTMB effort rather than raced. It tests kit, fueling, poles, feet, and, most usefully, your behaviour at an aid station at hour 14. Around it sit the biggest weeks of the plan, 90-120 km and 4,000-6,000 m of vertical. It should feel like a lot; it should not feel like a crisis. If it does, hold the Build 2 numbers instead - the body you have is the one racing, not the one on the spreadsheet.

Peak 2: weeks 17-20

The block most self-coached plans miss. Volume stays high but stops growing, and the specific rehearsals happen:

• A second-night session. One long run that starts between midnight and 02:00 after a normal day awake, 3-4 hours long. This is the closest you can get to the feeling of the second night without running 120 km first, and it is where people discover what their mind does when tired and dark coincide. The night running guide covers the equipment; this session covers the psychology.
• [Heat acclimation](/blog/heat-acclimation-trail-running) if late August tends to be hot, which in the Aosta valley on Saturday afternoon it often is.
• A full-kit long run. Mandatory equipment, poles, the pack you will race with, on a 6-8 hour day. Nothing should rub, and you should know where every item lives without looking.
• Feet. A blister-prevention protocol tested over the two longest days. Feet end more UTMB races between Courmayeur and Champex-Lac than anything except the stomach.

Taper: weeks 21-24

A three-week taper plus race week: volume down about 30%, then 50%, then 70%, intensity kept until ten days out, and the last long run of 3.5-4 hours in week 21. Sleep is a training variable now: bank it in race week rather than trying to "practise" being tired. Arrive in Chamonix early enough to adjust, and the altitude guide explains why arriving one to two days before a race that peaks at 2,500 m is the worst timing if you have the choice.

Fueling and sleep for two nights

A 38-hour UTMB burns well over 20,000 kcal. The plan is not to replace it but to keep the deficit slow enough that the brain keeps working: 60-90 g of carbohydrate an hour while the stomach cooperates, dropping to 40-60 g and simpler foods overnight, with real food from the aid stations (broth, bread, cheese, pasta) when sweet food stops being tolerable, which it will. Sodium and fluid get planned around the hot Saturday afternoon sections rather than the cold cols.

On sleep: most mid-pack finishers take no sleep at all, and some take one deliberate 15-20 minute nap at an aid station during the second night. Both work. What does not work is deciding in the moment, at 03:00, without a rule. Set the rule in training: either no sleep, or one nap at a named aid station if you arrive with a certain margin on the cutoff.

Pacing a 45-hour-30 cutoff

Effort-based, and the effort for the first 30 km is close to embarrassing. A sensible shape for a 38-hour plan:

• Chamonix to Les Contamines (about 30 km, 4-5 h). Jog, hike, chat. Nobody wins UTMB before Les Contamines; many lose it there.
• Les Contamines to Courmayeur (about 50 km, 11-13 h). Col du Bonhomme and Col de la Seigne in the dark and at dawn. Hike with poles, run only what is genuinely runnable, eat continuously, and arrive in Courmayeur with a written plan for the drop bag stop: a time limit, a change of socks, and a reason to leave.
• Courmayeur to Champex-Lac (about 45 km, 10-12 h). The Grand Col Ferret is the high point; the Swiss Val Ferret after it is long and runnable and where the gut usually starts to argue. Slow the intake rather than stopping it.
• Champex-Lac to Chamonix (about 49 km, 11-13 h). The second night. Bovine and Catogne are the climbs that break people, then the long last ascent out of Vallorcine before the descent to the finish. Everyone slows here. Plan to.

The general method is in the trail ultra pacing guide. The UTMB-specific rule: the halfway point of the effort is Champex-Lac, not Courmayeur, however the distance looks.

The mistakes I see most

• Training as if it were a long CCC. UTMB is not 100 km plus some. It is two nights, and the second one has to be rehearsed.
• Building volume and neglecting the hike. Runners arrive able to run 120 km a week and unable to climb Bonhomme efficiently at hour six.
• Under-training descents. 9,700 m of downhill. The quads decide whether the second half is running or shuffling.
• Too much racing in the build. One 100K rehearsal, and perhaps one shorter race. Every extra race costs a week of the peak.
• Reaching Courmayeur without a plan. The drop bag stop turns into an hour and the hour turns into a DNF.

What a coach changes here

Twenty-four weeks is long enough for almost everything to go wrong at least once: an injury in Build 1, a rehearsal race that goes badly, a family month that eats Peak 2. The plan on this page is the easy part. What a coach does is rewrite it every week around what actually happened, hold you back in week 14 when you feel good, and make the Courmayeur rule with you before the race so you do not have to make it at 06:00 on Saturday. If you want that, coaching is what I offer; if you are self-coaching, run the race readiness score at the end of Peak 1 and take the weakest dimension seriously.