When is the 2027 Arcachon triathlon?

The 2027 date has not been announced by the organisers yet. The 2026 edition took place on Saturday 3 October, with the XS at 10 am and the M at 1 pm, at the Plage des Arbousiers.

When does registration open for the 2027 Arcachon triathlon?

Not announced yet. In 2026 they opened from 22 June on Klikego (the M first for licence holders, then for everyone on 6 July), and both formats sold out.

Where does the race start?

Plage des Arbousiers, in Arcachon. Bibs are collected on race day only, from 8:30 am for the XS and from 11 am for the M. There is no dedicated car park: park in the nearby streets.

No. It is a non-drafting race, on roads open to traffic: the highway code applies.

Triathlon d'Arcachon: 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 5 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.

Triathlon d'Arcachon 2027: date, course and training plan

49.6 km · swim 1.5 · bike 38.5 · run 9.6Arcachon2027 edition: date not announced yet

The Arcachon triathlon, also called the Arca’Thlon, is raced in early October from the Plage des Arbousiers, on the Bassin d’Arcachon. One day, two triathlons: a solo XS in the morning and an M in the afternoon, solo or as a relay. The 2026 edition, on Saturday 3 October, hosted the Gironde Olympic-distance championship and sold out on both formats.

Your plan for Triathlon d'Arcachon

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

Your level?

14-day trial, cancel anytime.

Triathlon d'Arcachon at a glance

Date: 2027 edition: date not announced yet2026 edition: 3 October 2026
Formats: Triathlon MPlan below — 1.5 km swim in two loops with an Australian exit, 38.5 km bike in three loops, 9.6 km run in two laps (2026 distances). 1 pm start. Open from juniors upwards, 420 solo places and 50 relays of 2 or 3. In 2026: €60 for a licence holder, €82 without a licence (day pass included), €75 per relay of licence holders.
Triathlon XS — 400 m swim, 10.5 km bike, 3.1 km run (2026 distances). 10 am start, solo only, 150 places, open from benjamins (age 12) upwards. In 2026: €25 for a licence holder, €29 without a licence.
Registration: Entries for 2027 are not open and the date has not been announced. In 2026, entries were online only, on Klikego: opening was announced from 22 June, first for licence holders only on the M (it hosted the Gironde championship), then for everyone on 6 July at 10 am. Both formats sold out, and there are no on-site entries. Athletes without a licence take the day pass (included in the price) and fill in a health questionnaire.
Official website: triathlon-arcachon.com

The 2026 course

Start and transition at the Plage des Arbousiers. Swim: two 750 m loops in the Bassin for the M, with an Australian exit (one 400 m loop for the XS). Bike: three loops of about 13 km on open roads, via Le Moulleau, Les Abatilles, Pereire and the road along the Arcachon golf course, with two short climbs per lap; no aid station. Run: two laps along the seafront, from the Arbousiers towards Pereire and the Ville de Printemps, with an aid station on the circuit. The maps published on Klikego are the 2025 ones.

What the race asks of your training

A swim in the Bassin, in cool water

The site’s FAQ gives a water temperature of “around 16 °C”, and the rules make wetsuits mandatory below 16 °C (banned above 24 °C). Two 750 m loops with an Australian exit: a few open-water swims in September, in your wetsuit, and drills of exiting the water then swimming again prepare you well for this format.

A short looped bike course, with hills

Three loops of about 13 km via Le Moulleau, Les Abatilles and Pereire, on open roads, with two short climbs to around forty metres above sea level on each lap. No aid station on the bike, and drafting is banned: train your accelerations out of corners and short climbs in a big gear.

A seafront run, not quite flat

Two laps along the beach, between the Arbousiers and Pereire, with short rises to around twenty metres. Threshold sessions on a hilly route and bike-to-run bricks teach you to hold your pace over these short hills.

An end-of-season triathlon

In early October, the build-up happens over the summer: keeping your volume up in September, after the holidays, matters most. Watch the M cut-offs: 1 hour for the swim, start the run within 3 hours of the start and finish the first lap within 4 hours.

The plan below prepares the Triathlon M format, for an athlete at intermediate level with 5 days available per week. Until the official date is out, the example is set for October 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: 74
sessions / week: 5
peak week: 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
1	General preparation	4.4 h	17
2	General preparation	4.7 h	18
3	Base	5.3 h	12
4	Base	5.5 h	13
5	Baserecovery	4 h	10
6	Base	5.7 h	13
7	Build	6 h	14
8	Build	6.1 h	15
9	Buildrecovery	4.2 h	11
10	Specific	6.4 h	15
11	Specific	6.8 h	16
12	Specific	7 h	17
13	Taper	5.1 h	18
14	Taper	4.1 h	16
15	Race week	2.4 h	7

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.

MondaySwimmingEasy
39 min continuous swim
39 min · 1.8 km
TuesdayBrickHard
1 h 05 bike + 45 min run
including 3 × 10 min at threshold on the bike · run at threshold
1 h 58
FridaySwimmingHard
3 × 300 m at threshold
40 s recovery
37 min · 1.7 km
SaturdayCyclingEasy
1 h 44 at endurance pace
1 h 44
SundayRunningEasy
Long run 1 h 09
1 h 09 · 11.1 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 15-week build (recommended minimum: 8); a longest run never more than 8% above the previous month’s; 83% of the time at easy effort; a taper cutting volume by 66% in race week.

3 worth knowing · 19 checks passed

Remarks

Demanding sessions — Up to 4 demanding sessions in a single week (1 week(s)).
Strength training — No strength session.
Fueling — Long sessions (up to 128 min in this plan) are where race fueling is rehearsed.

The 19 checks passed, in detail

Length of the build — 15 weeks: enough for this race (recommended minimum: 8).
Sessions per week — 5 sessions a week: the minimum for this race is met.
Volume progression — Running volume rises smoothly from week to week.
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 83% of the time at easy effort: the most common distribution among trained endurance athletes.
Hard days back to back — Demanding sessions are separated by easy days.
Rest days — At least one rest day a week.
Bike-run bricks — 10 bike-run bricks over the last 12 weeks.
Taper — Volume drops 66% 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 (90%).
Swim / bike / run balance — Swim 21%, bike 46%, run 32%: within coaches’ benchmarks.
Frequency per discipline — Each discipline comes back at least 2 times a week.
Open water — 3 open-water session(s) before the race.
Longest ride — The longest ride lasts 120 min (benchmark: 90 to 150 min).
Longest run — The longest run lasts 80 min (benchmark: 60 to 105 min).
Swim distance — The longest swim covers 187% of the race distance.
Long ride increase — The long ride grows in small steps.

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.

Three disciplines, one load

Swim, bike and run are planned together: brick sessions, key sessions spread out, and a coherent total load week after week.

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

“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
“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
“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
“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

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 Triathlon d'Arcachon