When is the 2027 Trail des Aiguilles Rouges?

The 2027 date has not been announced yet. The 2026 edition took place on Sunday 27 September, with the TAR starting at 5 am and bib collection the day before in Chamonix.

What are the TAR cut-offs?

In 2026: Servoz (km 14.5) at 8 am, Planpraz (km 29) at 12:25 pm, La Flégère (km 42.5) at 3:45 pm and the finish at 6 pm, for a 5 am start.

How do you register for the Trail des Aiguilles Rouges?

Online on the official website when registration opens: in 2026, on 1 April at noon, until the 650 TAR places were gone. All three races sold out and there was no waiting list.

Trail des Aiguilles Rouges: 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.

Trail des Aiguilles Rouges 2027: date, course and training plan

50 km · 3,700 m D+Chamonix2027 edition: date not announced yet

The Trail des Aiguilles Rouges (TAR) is organised by the Chamonix Mont-Blanc Marathon club (CMBM) at the end of September (on the 27th in 2026). It is a loop of about 50 km and 3,700 m of climbing starting and finishing in Chamonix, in semi-self-sufficiency, on the trails of the Aiguilles Rouges massif, partly inside a nature reserve. Two shorter races, the P’tit TAR and the Mini TAR, start the same morning.

Your plan for Trail des Aiguilles Rouges

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

Your level?

14-day trial, cancel anytime.

Trail des Aiguilles Rouges at a glance

Date: 2027 edition: date not announced yet2026 edition: 27 September 2026
Formats: Trail des Aiguilles Rouges (TAR)Plan below — About 50 km and 3,700 m of climbing according to the 2026 rules (52 km in the 2026 split-time table), in semi-self-sufficiency. 5 am start from the Champ du Savoy in Chamonix, finishing at the same place. 650 runners at most.
P'tit TAR — About 18 km and 1,350 m of climbing, self-sufficient: no aid station on the course, only at the finish. 10 am start, 400 runners at most.
Mini TAR - Tom’s Trophy — About 8.4 km and 640 m of climbing, self-sufficient, on the south-facing side of the valley. Originally reserved for under-18s, it has been open to everyone since 2025. 9:45 am start, 200 runners at most.
Registration: Online on the official website. In 2026, registration opened on 1 April at noon and all three races sold out, with no waiting list. The TAR cost €80 (€73 without the welcome gift). Every runner had to complete the French Athletics Federation’s health prevention course (PPS) by 7 September. Bibs cannot be sold or swapped; a cancellation was refunded until 15 August, minus a €10 fee. Nothing has been published for 2027 yet.
Official website: aiguillesrouges.fr

The 2026 course

Start in Chamonix, climb to Merlet then Plan de la Cry, descent to Servoz, first aid station at km 14.5. The course then climbs again via Les Peutets and the Aiguillette des Houches to Le Brévent (km 26), then Planpraz, the second aid station at km 29. It carries on via the Col de la Glière, L’Index and the Lac Blanc turn-off to La Flégère, the last aid station at km 42.5, before dropping down via Charlanon to the finish in Chamonix, after 52 km and 3,700 m of climbing according to the organiser’s table.

What the race asks of your training

A lot of climbing over few kilometres

3,700 m of climbing for about 50 km, more than 70 m per kilometre, with long climbs up to Le Brévent (2,680 m of cumulative climbing at km 26) and then to L’Index. Hill sessions, long mountain runs and fast uphill hiking, with or without poles, matter more than flat mileage. Poles are allowed as long as you carry them from start to finish.

Cut-offs to plan for

In 2026: Servoz (km 14.5) at 8 am, 3 hours after the start, Planpraz (km 29) at 12:25 pm, La Flégère (km 42.5) at 3:45 pm, finish before 6 pm, so 13 hours at most. The first cut-off, after 880 m of climbing, is the tightest: setting off too slowly in the dark can cost you the race.

Only three aid stations

The TAR is run in semi-self-sufficiency: aid stations at Servoz, Planpraz and La Flégère, with no cups. You carry a water reserve, food and your own cup. Training with a loaded pack and testing your drink and food on long runs avoids bad surprises.

Late September at altitude

A 5 am start by headtorch, and high sections at Le Brévent and L’Index. The rules warn that winter conditions are “not rare at the end of September”: a winter kit (warm layer, hat, sometimes hiking crampons) can be added to the mandatory gear. It pays to get used to running in a jacket and full-length tights, and to technical descents on wet ground.

The plan below prepares the Trail des Aiguilles Rouges (TAR) format, for an athlete at intermediate level with 4 days available per week. Until the official date is out, the example is set for September 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: 60
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	1,061 m
2	General preparation	6 h	41	1,224 m
3	Base	6.3 h	43	1,171 m
4	Base	6.7 h	47	1,138 m
5	Baserecovery	5.3 h	37	914 m
6	Base	6.7 h	43	1,462 m
7	Build	7.5 h	49	1,514 m
8	Build	8.1 h	52	1,824 m
9	Buildrecovery	6.3 h	42	1,323 m
10	Specific	8.6 h	53	2,005 m
11	Specific	9 h	57	2,126 m
12	Specific	9.7 h	61	2,389 m
13	Taper	6.1 h	40	1,288 m
14	Taper	4.8 h	35	429 m
15	Race week	3.4 h	28	71 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
10 × 1 min 30 s uphill
recover on the way down, 2 min 15 s
1 h 03 · 6.3 km
FridayEasy
1 h 15 easy
1 h 15 · 8.8 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 65% 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 65% 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 (100%).
Climbing in the busiest week — The busiest week climbs 2389 m, for 3700 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 Trail des Aiguilles Rouges