Salomon EcoTrail Paris: Course, Elevation & Route Profile

Course & Elevation

The start is on Saturday morning between 09:00 and 09:15 at the Château de Rambouillet, some 50 kilometres south-west of Paris at a little over 145 metres. From there the route crosses the forests, hillsides and paths of the western Île-de-France, with a long section through the Vallée de Chevreuse and past its châteaux.

Across all 123 kilometres the profile is remarkably uniform: the course oscillates almost throughout between 110 and 175 metres, never dropping below 28 or rising above 190. Forty-two percent of it is level, 21 percent uphill and 26 percent downhill, and the steepest drag measures 1.2 kilometres at 6.7 percent at kilometre 57. The densest cluster of climbs sits between kilometre 49 and 63 – in the middle of the night for most of the field.

The last ten kilometres fall from around 130 metres to 30 and follow the Seine into central Paris, finishing on the Pont d'Iéna directly beneath the Eiffel Tower. In total 1,773 metres of ascent against 1,886 of descent; the organiser publishes 2,000 metres. The cut-off is 21 hours 15, and the race is a UTMB 100K qualifier.

Pacing Strategy

An ultra without real climbs is not an easier ultra, it is a different one. There is no gradient here that forces you to walk and thereby unloads your running muscles: across 123 kilometres you run almost throughout. That makes early discipline more important than on any mountain ultra – run the first thirty kilometres at a pace that feels almost embarrassingly slow.

The race is decided between kilometre 49 and 70. That is where the course's climbs bunch most densely, in darkness for most runners and after eight to ten hours on your feet. Use those short rises deliberately as walking breaks even though they are runnable – they are the only built-in recovery this course offers.

The trap is the last ten kilometres. From 130 metres down to 30, on made paths along the Seine, with the lit Eiffel Tower in view: the course gets fast, the field lifts, and your legs have 110 kilometres of continuous running behind them. Plan that stretch as a race of its own and deliberately keep something back until kilometre 113.

Training plan for Salomon EcoTrail Paris: 12-week build

Expect 12 to 21 hours; the cut-off is 21:15. The demand is unusual for a 120: a very long, almost continuously runnable aerobic effort with over forty percent of the course flat and not a single climb longer than a kilometre and a half.

Training therefore emphasises running volume and fatigue resistance rather than climbing strength. Long runs of five to seven hours on rolling woodland track with 600 to 1,000 metres of ascent model the demand; back-to-back weekends with two long runs on consecutive days are worth more here than any single mountain session.

The race-deciding phase is the night. For most runners ten to sixteen hours fall in darkness, on forest paths west of Paris. Do at least two long runs entirely at night with a head torch, test the full mandatory kit, and rehearse a fuelling strategy across twelve hours and beyond.

On conditions: mid-to-late March in the Île-de-France means cool to cold nights, frequently wet woodland ground and several degrees between a nine o'clock start and the small hours. Plan a layering system rather than a jacket, train on mud, and factor the ten fast closing kilometres on tarmac and made paths into your shoe choice.