When is the TDS 2027?

The date has not been announced yet. In 2026, the race started on Monday 24 August at 11:50 pm in Courmayeur, opening UTMB Mont-Blanc week, which ran from 24 to 30 August.

Do you need Running Stones to run the TDS?

Not in 2026: the TDS was not drawn by lottery and no Running Stone was required. You did, however, need a valid UTMB Index in 100K or 100M, and had to register quickly, first come, first served. Finishing the TDS earns 4 Running Stones. The 2027 conditions have not been published yet.

What is the TDS time limit?

44h55 in 2026, meaning a finish in Chamonix by Wednesday evening at the latest. Cut-offs are set along the course: a runner who leaves a checkpoint after its time limit is out of the race.

TDS (Sur les Traces des Ducs de Savoie): how many weeks of preparation?

For an athlete at intermediate level, Endu builds a 24-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 5 sessions per week. You choose 5 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?

Not as a first long race: if you declare a beginner level, Endu flags it. Aim for a shorter race of the same kind first; Endu builds that preparation too.

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.

TDS (Sur les Traces des Ducs de Savoie) 2027: date, course and training plan

145 km · 9,500 m D+Courmayeur2027 edition: date not announced yet

In the Tracks of the Dukes of Savoy, the TDS is one of the races of UTMB Mont-Blanc week: 145 km and 9,500 m of climbing in 2026, from Courmayeur, in the Aosta Valley, to Chamonix, through the Tarentaise and the Beaufortain. It starts in the middle of the night, at 11:50 pm, with 44h55 to finish. The organisers describe it as beautiful, technical, wild and demanding. The 2027 date has not been announced yet.

A demanding distance: it is wiser to have finished a shorter race of the same kind first.

Your plan for TDS (Sur les Traces des Ducs de Savoie)

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

Your level?

14-day trial, cancel anytime.

TDS (Sur les Traces des Ducs de Savoie) at a glance

Date: 2027 edition: date not announced yet2026 edition: 24 August 2026
Formats: TDSPlan below — 145 km and 9,500 m of climbing in 2026. Start in Courmayeur on Monday 24 August 2026 at 11:50 pm, finish in Chamonix. Time limit: 44h55. A 100M-category race on the UTMB World Series circuit: finishers receive 4 Running Stones. €320 in 2026.
Les autres courses de la semaine — The same week, UTMB Mont-Blanc also hosts the UTMB, CCC, OCC, 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 TDS did not go through the lottery: places were allocated first come, first served, from 13 January 2026 at 11 am (Paris time), and the race is shown as full. You needed a valid UTMB Index in the 100K or 100M category, with no Running Stone required. 2026 price: €320, including transport to the start. Open to runners born in 2006 or earlier. Entries are personal and cannot be transferred; to get a refund if you cancel, you must take out the insurance when you register.
Official website: montblanc.utmb.world/fr/races/TDS

The 2026 course

Start in Courmayeur (1,222 m) at 11:50 pm. Climb to Checrouit – Maison Vieille and the Arête du Mont-Favre (2,412 m), past Lac Combal, then the Col Chavannes (2,580 m) and a long descent towards La Thuile and the Little St Bernard Pass. The course enters France, drops to Séez and Bourg-Saint-Maurice (831 m), climbs back up to the Fort de la Platte and the Passeur de Pralognan (2,554 m), then reaches the Cormet de Roselend, the Col de la Sauce and La Gittaz. Next comes the Beaufortain: the Pas d’Outray, facing the Pierra Menta and the Grand Mont, Beaufort (739 m, hot meal), Hauteluce, the Girotte dam and Le Signal. Down to Notre-Dame-de-la-Gorge and Les Contamines, a last big climb past the Chalets du Truc to the Col de Tricot (2,117 m), then Bellevue, Les Houches and the finish in Chamonix.

What the race asks of your training

A sleepless night from the start

The start is at 11:50 pm and the Arête du Mont-Favre, at 2,412 m, is crossed in the dead of night. With a 44h55 time limit, many runners also spend the following night out on the course. A few long runs started in the evening or before dawn teach you to run by headtorch, to keep eating through tiredness and to manage sleep.

Passes above 2,500 m

On the official 2026 profile, the Col Chavannes tops out at 2,580 m and the Passeur de Pralognan at 2,554 m, before the Cormet de Roselend, the Col de la Sauce and, late in the race, the Col de Tricot. Long climbs at a brisk hiking pace, with or without poles, and mountain weekends above 2,000 m prepare you for these 9,500 m of climbing better than short repeats.

Technical descents on tired legs

The course drops several times to the valley floor: from La Thuile to Bourg-Saint-Maurice (831 m), then to Beaufort (739 m) and Notre-Dame-de-la-Gorge. The organisers stress how technical the terrain is. Practising descents on trails, along with leg strength work, saves you from losing hours in the second half.

Semi-self-sufficiency and the pack

The rules require you to reach the next aid station on your own, with enough to drink, eat and stay warm, and to carry all the mandatory kit from start to finish. On the TDS, missing a water reserve, a hooded waterproof jacket, a light, a survival blanket or a smartphone means 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 TDS format, for an athlete at intermediate level with 5 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: 24
sessions: 109
sessions / week: 5
peak week: 14 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 3–10 · 8 wk
Build
Weeks 11–16 · 6 wk
Specific
Weeks 17–21 · 5 wk
Taper
Weeks 22–23 · 2 wk
Race week
Weeks 24–24 · 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	7 h	47	1,359 m
2	General preparation	7.3 h	49	1,550 m
3	Base	7.6 h	50	1,676 m
4	Base	8 h	52	1,782 m
5	Base	8.3 h	54	1,875 m
6	Baserecovery	6.7 h	46	1,240 m
7	Base	8.3 h	54	1,962 m
8	Base	9.1 h	59	2,167 m
9	Base	9.5 h	61	2,280 m
10	Baserecovery	7.4 h	50	1,514 m
11	Build	9.5 h	61	2,312 m
12	Build	10.3 h	63	2,500 m
13	Build	10.8 h	67	2,691 m
14	Buildrecovery	8.4 h	55	1,899 m
15	Build	10.8 h	66	2,705 m
16	Build	11.8 h	74	3,018 m
17	Specific	12.3 h	75	3,194 m
18	Specificrecovery	9.6 h	62	2,102 m
19	Specific	12.3 h	75	3,150 m
20	Specific	13.4 h	82	3,561 m
21	Specific	14 h	88	3,330 m
22	Taper	9.2 h	60	2,213 m
23	Taper	7.1 h	49	902 m
24	Race week	3.7 h	31	115 m

Sample week — week 13 (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.

TuesdayModerate
3 × (8 min climb + 4 min descent)
51 min · 6 km
WednesdayEasy
49 min easy
49 min · 5.7 km
FridayEasy
49 min easy
49 min · 5.7 km
SaturdayEasy
Back-to-back long run
2 h 39 · 16 km
SundayEasy
Long run 5 h 41
5 h 41 · 34 km

Example generated for a intermediate-level profile (MAS 15 km/h, 5 days available per week). Your plan will depend on your level, availability and feedback.

This plan’s check-up

Pass

A 24-week build (recommended minimum: 20); a longest run never more than 10% above the previous month’s; volume rising at most 9% 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.

3 worth knowing · 15 checks passed

Remarks

Lighter weeks — 5 loading weeks in a row without a lighter week (up to week 5).
Strength training — No strength session.
Fueling — Long sessions (up to 420 min in this plan) are where race fueling is rehearsed.

The 15 checks passed, in detail

Length of the build — 24 weeks: enough for this race (recommended minimum: 20).
Sessions per week — 5 sessions a week: the minimum for this race is met.
Volume progression — Running volume rises at most 9% from one week to the next (a signal appears beyond 20%).
Long run increase — Each week, the longest run is at most 10% longer than the longest of the previous month (benchmark: 10%).
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 (37 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 (95%).
Climbing in the busiest week — The busiest week climbs 3561 m, for 9500 m on race day.
Back-to-back long runs — The plan has back-to-back long runs (9 weekends).

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 5 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 TDS (Sur les Traces des Ducs de Savoie)