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Race course · EcoTrail Paris 2027

EcoTrail Paris 45 km: elevation profile, gain and key sections

The 45 km race of the EcoTrail Paris starts in the gardens of the Château de Versailles and finishes at the foot of the Eiffel Tower, on the Pont d'Iéna. On paper, it's a "fast" trail. In practice, the elevation gain isn't spread evenly: the race is decided between kilometre 20 and kilometre 38. Here is the course section by section, with the official figures.

Updated 19 October 2026 · race on Saturday 20 March 2027

Race facts

800 m of gain? What the measurements really say

Depending on the source, the same course shows a very different elevation gain (D+):

These gaps don't mean one source is wrong. Elevation gain depends on how you smooth the small altitude variations of a track: counting every tiny bump inflates it, smoothing more flattens it. The course also changes slightly from one edition to the next. The organiser's provisional 2027 GPX, run through Runcon, gives 788 m: keep a ballpark of 750 to 800 m in mind, and above all where that gain sits: that's what decides your race.

The course profile, analysed by Runcon

Here is the course as Runcon displays it when you add a race: each stretch is coloured by the effort it takes, from blue for descents to brick red for the hardest climbs. This profile is built from the provisional 2027 GPX published by the organiser.

"Provisional course" 2027 GPX published by the organiser. It measures 47.7 km, a little more than the official 47.1 km, so its kilometres run slightly ahead of the race markers (about 0.3 km at Chaville, 0.6 km at the finish). The dotted lines mark the Chaville and Saint-Cloud aid stations.

What the profile shows at a glance: the first half alternates flat ground and small bumps, with two short, sharp climbs around km 14 and 17.5. Then, after Chaville, four of the six steep climbs on the course come one after another, including the hardest, around 13% over 460 m near km 26. After Saint-Cloud, the profile flattens out all the way to the finish.

The steep climbs, one by one

Runcon's briefing counts the steep stretches of the course. In trail running, a climb is steep between 6 and 9% average gradient, and very steep above 9%. A descent is steep beyond 6%. On the EcoTrail 45 km, that gives:

Most of them are short: four of the six climbs are under 500 m. They are sharp kicks you get over in a few minutes, often walking. Here they are in the order you'll meet them:

Two climbs are longer than 500 m, in bold in the table, and those are the ones to prepare for:

• Km 27.4 to 28.1: 620 m at 12.0%. This is the climb that costs the most time on the whole course. It comes right after the hardest one (12.9% at km 25.8) and a long, steep 1.2 km descent at −8.1%: up, down, up again, all within two kilometres. It's the heart of the course.
• Km 30.5 to 31.2: 690 m at 6.3%. Less steep, but it's the longest, and it comes at kilometre 30, when your legs have already absorbed the previous stretch.

As for descents, seven are steep, and four are longer than 500 m: at km 12.5 (560 m at −8.5%), just before Chaville at km 19.7 (510 m at −10.1%), at km 37.8 before Saint-Cloud (610 m at −6.1%) and above all 1.2 km at −8.1% at km 26.3, squeezed between the two hardest climbs. To train for it, a few repeats of 500 to 600 m at 8 to 12% cover most of what the race asks of you uphill, and the descent that follows matters as much as the climb.

The three sections of the course

The two aid stations naturally split the race into three. Their positions and the cumulative elevation gain at each checkpoint come from the official tracking of the 2026 edition.

Elevation gain per kilometre, section by section

Width of each bar = length of the section

Source: LiveTrail checkpoints, 2026 edition.

1. Versailles → Chaville (km 0 to 20.6): the warm-up

A little under 40% of the elevation gain over almost half the distance. The wave start and the excitement of the Versailles gardens push you to go out too fast: this is the section where you gain the least time and where you can lose the most, later on. First aid station at the Jean-Jaurès stadium in Chaville.

2. Chaville → Saint-Cloud (km 20.6 to 38.0): where the race is decided

Half the total elevation gain in 17 km, with an average gradient 50% steeper than in the first part. And it comes at the worst moment: you already have 20 km in your legs, and no aid station until the Domaine national de Saint-Cloud, at km 38. Plan your water and gels for these 17 km in one go, and accept walking on the steepest climbs: by the finish, it's often faster than wearing yourself out on them.

3. Saint-Cloud → Pont d'Iéna (km 38.0 to 47.1): the fast finish

Nine almost flat kilometres to the finish, with a last checkpoint on the Île aux Cygnes (km 45.5). On paper, it's the easy part. In practice, this is where you pay for running section 2 too fast: your legs still have to push on the flat, and every kilometre shows on the clock. Runners who kept something in reserve in section 2 overtake here.

Aid stations and cut-off times

Times from the 2026 edition, for a 10:00 start. They give a good idea of the minimum pace to hold; check the 2027 times in the official roadbook before the race.

Watch out: the tightest cut-off is the first one. A runner who simply aims to finish needs to hold a little under 9'30" per kilometre as far as Chaville, and then has more margin afterwards. For the 2027 edition, the organiser announces a time limit of 8h15.

In 2026, the leaders crossed the line a little over 3h10 after the start, and the last finishers came in around 8h15.

Read the course in detail with Runcon

The profile above is what Runcon shows for any race as soon as you drop in its GPX. In the app, you also get an estimated finish time based on your level, split times at the aid stations, the section that will cost you the most, and a pre-race briefing that counts the steep climbs and descents and details those longer than 500 m. The organiser has published a provisional 2027 GPX: drop it in to get the analysis for your level, and do it again if a final route comes out before the race.

No GPX yet? Our GPX file guide explains where to find one and how to draw one in the meantime.

Frequently asked questions

When is the EcoTrail Paris 45 km in 2027?

On Saturday 20 March 2027, with a wave start between 10:00 and 10:15.

How many steep climbs are there on the EcoTrail 45 km?

Six on the provisional 2027 GPX: one steep (6 to 9%) and five very steep (over 9%). Only two are longer than 500 m, at km 27.4 and 30.5. The hardest climbs at 12.9% over 460 m around km 25.8. Details above.

How do I get to the start?

The organiser recommends the RER C to Saint-Cyr station, then a free shuttle bus to the start area. Detailed times are in the official roadbook.

Can I still sign up?

At the time of writing, entries for the 45 km are closed. The race page offers a waiting list and a bib resale alert.

What gear is mandatory?

Among other things, at least 0.5 L of water, food, a 15 cl cup, a survival blanket, a charged phone and an ID. The full list and penalties are on the official race page.

Do I need a licence or a medical certificate?

When collecting your bib, you need a 2026-2027 FFA (French Athletics Federation) licence or a PPS certificate (Parcours Prévention Santé, the French online health-awareness course required for non-licensed runners).

Sources

• Official Trail 45 km page (EcoTrail Paris)
• Checkpoints of the 2026 edition (LiveTrail)
• Provisional 2027 GPX of the Trail 45 km (EcoTrail Paris, on Strava)
• ITRA 2025 race page and ITRA 2022 race page

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