When is the OCC 2027?

The date has not been announced yet. In 2026, the race started on Thursday 27 August at 8:15 am in Orsières, during UTMB Mont-Blanc week, which ran from 24 to 30 August.

Where does the OCC (Orsières-Champex-Chamonix) start?

From Orsières, at 915 m, in the Val d’Entremont (Valais, Switzerland). In 2026, the start was at 8:15 am and transport to the start was included in the entry. The finish is under the arch in the centre of Chamonix.

How do you get into the OCC?

By lottery, held in January for the summer race in 2026. You need at least one Running Stone earned in the previous 24 months on a UTMB World Series race, and a valid UTMB Index in 20K, 50K, 100K or 100M. The more Running Stones you hold, the better your chances. Charity bibs give entry without the lottery, under the same conditions.

OCC (Orsières-Champex-Chamonix): how many weeks of preparation?

For an athlete at intermediate level, Endu builds a 15-week preparation. If your race is closer, the plan compresses phases while keeping the taper; if it's further away, it lengthens the preparation, and when the gap is large the preparation starts right away, gently and at your current volume, before building up.

How many sessions per week?

This example has 4 sessions per week. You choose 4 to 7 training days and the exact days (e.g. Tue, Thu, Sat, Sun): the plan sticks to them.

I'm a beginner, is this plan for me?

The plan adapts to your declared level (beginner to semi-pro): starting volume, progression and intensity change. Endu also offers a "Discovery" mode without a race to build a base first.

Can I follow sessions on my watch?

Yes, on Garmin and COROS. On Garmin, the Endu app (Connect IQ Store) shows today’s session and starts it as a guided workout. On COROS, link your account from your profile: your running, trail and cycling sessions land in the watch calendar. Other brands are not supported yet.

How much does it cost?

14-day free trial, then €7.99/month with no commitment or €59.88/year (€4.99/month). Unlimited objectives and sports.

OCC (Orsières-Champex-Chamonix) 2027: date, course and training plan

60 km · 3,500 m D+Orsières2027 edition: date not announced yet

The OCC links Orsières, in the Swiss Valais, to Chamonix: 60 km and 3,500 m of climbing in 2026, via Champex-Lac, Trient, the Col de Balme and Vallorcine. It is the 50K-category final of the UTMB World Series circuit, run on the Thursday of UTMB Mont-Blanc week, and entry is by lottery, with Running Stones. The 2027 date has not been announced yet.

Your plan for OCC (Orsières-Champex-Chamonix)

A plan set to your level and free days, which adapts to your feedback after each session.

Your level?

14-day trial, cancel anytime.

OCC (Orsières-Champex-Chamonix) at a glance

Date: 2027 edition: date not announced yet2026 edition: 27 August 2026
Formats: OCCPlan below — 60 km and 3,500 m of climbing in 2026. Start in Orsières on Thursday 27 August 2026 at 8:15 am, finish under the arch in the centre of Chamonix. Time limit: 14h30. The UTMB World Series 50K final: finishing the OCC does not earn a Running Stone. €199 in 2026, including transport to the start.
Les autres courses de la semaine — The same week, UTMB Mont-Blanc also hosts the UTMB, CCC, TDS, PTL, MCC, ETC and YCC, among others. A runner may only take part in one race during the week.
Registration: The 2027 entry conditions have not been published yet. In 2026, the OCC was drawn by lottery: pre-registration from 8 January 2026 at 11 am to 19 January 2026 at 11:59 pm (Paris time), results on 22 January, then confirmation and payment before 4 February. To enter the draw, you needed at least one Running Stone earned in the previous 24 months and a valid UTMB Index in 20K, 50K, 100K or 100M. Each Running Stone counts as one chance; once your entry is confirmed, all your Running Stones are used up, and a drawn runner who fails to confirm in time loses half of them. Group pre-registration was possible, and charity bibs, offered in December, gave entry without the lottery under the same conditions. 2026 price: €199. Open to runners born in 2006 or earlier. Entries cannot be transferred, and are only refunded if you took out the cancellation insurance when registering.
Official website: montblanc.utmb.world/fr/races/OCC

The 2026 course

Start in Orsières (915 m), in the Val d’Entremont. Climb to Champex-Lac (1,469 m, km 7, drinks), then Plan de l’Au (km 12) and La Giète (1,890 m, km 19), before the descent to Trient (1,304 m, km 24, aid station). A long climb past the Chalet des Grands to the Col de Balme (2,202 m, km 34), on the French-Swiss border, then the Tête de Balme (2,321 m), the high point. The course drops back to the Swiss side, re-enters France above Vallorcine, crosses the Col des Posettes (km 42) and descends to Le Tour (km 47), then Argentière (km 50, aid station). It ends along the lower north-side balcony paths of the valley and La Joux, to the finish arch in the centre of Chamonix, at km 61 on the official profile.

What the race asks of your training

A start that climbs straight away

From Orsières (915 m), the race climbs to Champex-Lac (1,469 m) within the first 7 km, then to La Giète (1,890 m) before dropping down to Trient. Long hill sessions and mountain runs, running then power-hiking when the slope steepens, teach you to get through this opening without going into the red.

The Col de Balme in the second half

After Trient (km 24), the longest climb of the course leads to the Col de Balme (2,202 m, km 34), on the border, then to the Tête de Balme (2,321 m), the course’s new high point in 2026. You still need strength at that stage: linking two climbs at the end of a long run, and leg strength work for the descents to Le Tour and Argentière, prepares you for it.

Cut-offs to watch

In 2026: Plan de l’Au (km 12) at 11:15 am, Trient (km 24) at 2:15 pm, Col de Balme (km 34) at 5:30 pm, Argentière (km 50) at 9:15 pm and the finish in Chamonix at 11:30 pm. The first comes 3 hours after the start, for 12 km and more than 700 m of climbing: a few long runs at your planned race pace keep you from starting too slowly.

Semi-self-sufficiency and the pack

The rules require you to leave each aid station with enough to reach the next one and to carry all the mandatory kit, with no disposable cups. On the OCC, missing a water reserve, a hooded waterproof jacket, a light, a survival blanket or a smartphone means immediate disqualification. Do your long runs with a loaded pack and test in training what you will eat in the race.

The plan below prepares the OCC format, for an athlete at intermediate level with 4 days available per week. Until the official date is out, the example is set for August 2027. Aiming for another format? Enter its distance when you create your plan, which will be calibrated on your level, your available days and your feedback after every session.

weeks: 15
sessions: 59
sessions / week: 4
peak week: 9.7 h

Plan structure

Periodised in phases: build the base, move to race-specific work, then taper before the race.

General preparation
Weeks 1–2 · 2 wk
Base
Weeks 3–6 · 4 wk
Build
Weeks 7–9 · 3 wk
Specific
Weeks 10–12 · 3 wk
Taper
Weeks 13–14 · 2 wk
Race week
Weeks 15–15 · 1 wk

Volume progression

Week by week: lighter recovery weeks are built in to absorb the load.

Wk	Phase	Hours	km	Elev.
1	General preparation	5.6 h	38	1,012 m
2	General preparation	6 h	41	1,200 m
3	Base	6.3 h	44	1,127 m
4	Base	6.7 h	47	1,092 m
5	Baserecovery	5.3 h	37	862 m
6	Base	6.7 h	45	1,405 m
7	Build	7.5 h	51	1,475 m
8	Build	8.1 h	52	1,767 m
9	Buildrecovery	6.3 h	42	1,287 m
10	Specific	8.6 h	54	1,944 m
11	Specific	9 h	57	2,072 m
12	Specific	9.7 h	61	2,303 m
13	Taper	6.1 h	40	1,228 m
14	Taper	3.5 h	27	312 m
15	Race week	2.6 h	22	67 m

Sample week — week 8 (Build)

Real sessions from the plan with their targets. Each session is detailed step by step, and can be sent to a Garmin or COROS watch.

TuesdayVery hard
11 × 1 min 30 s uphill
recover on the way down, 2 min 15 s
1 h 06 · 6.6 km
FridayEasy
1 h 12 easy
1 h 12 · 8.4 km
SaturdayEasy
Back-to-back long run
1 h 36 · 10 km
SundayEasy
Long run 4 h 10
4 h 10 · 27 km

Example generated for a intermediate-level profile (MAS 15 km/h, 4 days available per week). Your plan will depend on your level, availability and feedback.

This plan’s check-up

Pass with remarks

A longest run never more than 8% above the previous month’s; volume rising at most 12% from one week to the next; 95% of the time at easy effort; the longest session 3 weeks before the race; a taper cutting volume by 73% in race week.

1 worth a look · 2 worth knowing · 14 checks passed

Remarks

Length of the build — Short build: 15 weeks up to the race (recommended minimum: 16). If your build started before the weeks checked, add the weeks already done.
Strength training — No strength session.
Fueling — Long sessions (up to 290 min in this plan) are where race fueling is rehearsed.

The 14 checks passed, in detail

Sessions per week — 4 sessions a week: the minimum for this race is met.
Volume progression — Running volume rises at most 12% from one week to the next (a signal appears beyond 20%).
Long run increase — Each week, the longest run is at most 8% longer than the longest of the previous month (benchmark: 10%).
Lighter weeks — A lighter week comes back regularly (weeks 5, 9, 13).
Intensity distribution — About 95% of the time at easy effort: the most common distribution among trained endurance athletes.
Demanding sessions — No more than 2 demanding session(s) a week: suited to the level.
Hard days back to back — Demanding sessions are separated by easy days.
Rest days — At least one rest day a week.
Climbing in training — The plan prepares the climbs and descents (33 sessions with elevation).
Timing of the longest session — The longest session falls 3 weeks before the race: the right time.
Taper — Volume drops 73% in race week.
Intensity during the taper — Short race-pace efforts remain in the last two weeks.
Frequency during the taper — The number of sessions stays close to usual (88%).
Climbing in the busiest week — The busiest week climbs 2303 m, for 3500 m on race day.

Endu runs its own plans through the plan check open to everyone: same public rules, same thresholds, same sources. The rules and their sources, and a check of your own plan.

Why this plan works

Science-based periodisation

Base → build → specific → taper, with a recovery week every 3 to 4 weeks. Load goes up, but never two hard weeks in a row without a breather.

Paces, not vague feelings

Every session has target zones (pace, HR) computed from your MAS or a reference performance. A MAS test is built into the plan if you don't know yours.

Elevation as the central variable

Weekly climbing volume, long hilly runs, downhill technique and power-hiking for ultras: a trail plan is not a road plan with bumps.

A plan that listens

After each session you rate how it felt (RPE). Too hard? The plan eases what follows. Skipped a session? It reschedules or absorbs it.

On your watch

On Garmin with the Endu app, on COROS by direct sync: the guided workout shows up on your wrist, step by step.

Reviews

What our users say.

4.8/5

“I took Endu to prepare a trail race with friends. I really like having my week already organised: it motivates me and I enjoy my runs more.”
Émilie · Trail
“What I like is no longer asking myself a thousand questions before going for a run. I follow the plan and I enjoy training.”
Nicolas · Trail
“With work and the kids, I thought I’d struggle to follow a plan. In the end, having a structure helps me a lot. Running has found a real place in my week again, and it feels good!”
Julie · Trail
“I used to spend more time looking for a plan than following one. Now I have my sessions, I know what to do and I stick to it. Really glad I tried it.”
Thomas · Running
“Training for my first half marathon and honestly, I’m getting into it! I even look at my next sessions ahead of time, when before I was mostly looking for an excuse not to go out 😂”
Camille · Running
“Simple to follow and really handy with the watch. I start my session and off I go.”
Julien · Running
“A good find to prepare my swimrun! It’s nice to find a plan for this sport. I’ve recommended it to my teammate.”
Antoine · Swimrun
“I run more regularly and, above all, with more desire. For that alone, I’m delighted.”
Laura · Swimrun
“For triathlon, having all three sports in the same schedule really makes my life easier. I spend less time organising my training and I still enjoy following it just as much.”
Maxime · Triathlon
“At first I just wanted to try it. Now checking the next day’s session has become my little evening ritual 😊”
Sarah · Triathlon

Your plan, not a template athlete's

This plan is generated for an athlete at intermediate level with 4 days available per week. Yours will be calibrated on your MAS, your available days and your feedback after every session. 3 minutes. 14-day trial, cancel anytime.

Create my plan for OCC (Orsières-Champex-Chamonix)