Marathon du Lac du Der.
The Marathon du Lac du Der runs point to point, from the centre of Saint-Dizier to the harbour at Giffaumont-Champaubert on the shore of France's largest artificial lake. In between come canal embankments, woodland and a long stretch on the lake dyke: flat overall, with short ramps that only start to matter in the second half.
Marathon du Lac du Der 2027: Course, Route Profile & Map
The start is on Avenue de Belle Forêt-sur-Marne, opposite the Parc du Jard. The opening kilometres loop through central Saint-Dizier and come back close to the start around kilometre five. From there the course climbs onto the embankments of the Canal d'amenée, the feeder canal that fills the lake, and heads south-west via Valcourt and Éclaron towards the water. Up to kilometre 16 everything stays between 135 and 148 metres, little more than a ripple.
From kilometre 17 the ground gets busier. A first hump, then at kilometre 20.7 the most distinct spot of the day: just over half a kilometre at three to almost six percent up onto the dyke at La Cornée du Der, where the relays also change over. From here the route runs on and beside the lake dyke, anticlockwise round the north shore past Sainte-Marie-du-Lac and Larzicourt, down the west shore and along the south shore to Giffaumont. It sheds height slowly in short waves and finishes about ten metres lower than it started.
The lake gives the day its character: water on one side, woods and forest on the other, and the lake's birdlife, which the organiser itself singles out. The local running club CAP DER from Montier-en-Der has organised the race since 2013; 2027 is the 14th edition, with roughly 2,000 to 2,500 runners across all formats. Many points along the course are easy for supporters to reach, and shuttles link the finish and the start.
| Start | Length | Ø | Max. | Gain | Cat. |
|---|---|---|---|---|---|
| km 20.7 | 0.6 km | 3.3 % | 5.8 % | +19 m | — |
Climb categories follow the road-cycling convention and rate the terrain itself (length and gradient) regardless of sport: Cat. 4 marks the easiest rated climbs, Cat. 1 the hardest, and HC (hors catégorie, “beyond categorization”) is reserved for the most brutal ascents. Short climbs below the Cat. 4 threshold stay unrated.
How to pace Marathon du Lac du Der.
Start under control
The first half is where you save time by not chasing it. The town loop and the canal embankments are flat and even, and the pace feels easier there than it is. Run strictly at goal rhythm until kilometre 17 and use the groups that form on the long straight embankment sections.
Hold your rhythm
The race is decided between kilometre 17 and the finish. The ramp onto the dyke at La Cornée du Der, at kilometre 21, costs only a few seconds if you run it by feel rather than by the watch. After that the lakeshore brings many short waves, none of them long, but together enough to break a rhythm that was set too high. Keep your effort constant on them and let the pace dip briefly.
Spend what is left
The biggest trap is the dyke itself: open, looking the same for kilometre after kilometre, and with little shelter if wind comes across the water. Running it alone costs more than any of the ramps. Find a group for the last 20 kilometres and save any increase in pace for the final five along the south shore.
Training plan for Marathon du Lac du Der: 12-week build
Build the base
For most age-group runners the Marathon du Lac du Der means three to five hours of steady aerobic work, within a six-hour time limit. The profile is flat, so the load is almost pure endurance with no long climbs; what matters is holding marathon pace calmly over the whole distance.
Train race pace
The decisive phase is the second half along the lake, where short waves and open dyke sections disturb your rhythm. Build long runs so the last 10 to 15 kilometres are at marathon pace on gently rolling ground, ideally somewhere open to the wind. Add a few short ramps of half a kilometre at goal rhythm so the climb onto the dyke at kilometre 21 does not knock you out of your stride.
Rehearse the course
The race is held in mid-June with a 7:30 start. Besides aid stations every five kilometres the organiser sets up separate cooling zones in between, a sign that warmth can be a factor on the day. Practise drinking and taking gels at pace, and schedule some long runs on warmer mornings.
Arrive fresh
Because start and finish are 30 kilometres apart, logistics are part of the preparation too: an early shuttle from the finish to the start, and bib collection on Saturday only. A calm race morning saves energy you will want on the lakeshore.
Courses
Download the Marathon du Lac du Der course as a GPX file for your watch or bike computer.
Let YOUB adapt your plan for Marathon du Lac du Der dynamically
Ben connects your goal, the course, current load, recovery, and calendar. Your plan stays pointed at race day even when real life is not perfectly plannable.
Everything about Marathon du Lac du Der.
How long is Marathon du Lac du Der?
Marathon du Lac du Der is 42.2 km long. That distance shapes how much aerobic endurance, pace durability, and race-specific work belong in the training plan.
How much elevation gain does Marathon du Lac du Der have?
Marathon du Lac du Der has around 269 m of elevation gain over 42.2 km. That affects pacing, muscular load, and preparation for late-race sections.
What is the route profile of Marathon du Lac du Der?
Marathon du Lac du Der is classified as Flat, averaging 6.4 vertical metres per kilometre. 57% of the route is flat, 22% climbs moderately (2 to 6%) and 0% is steeper than 6%.
What climbs does Marathon du Lac du Der have?
The hardest climb of Marathon du Lac du Der starts at kilometre 20.7, runs for 0.6 km at an average of 3.3% and gains 19 metres.
Is Marathon du Lac du Der a loop course?
No, Marathon du Lac du Der is a point-to-point course: start and finish are in different places.
Is there a GPX file for the Marathon du Lac du Der course?
Yes. The Marathon du Lac du Der course is on this page as a free GPX download — ready to import into Garmin, Wahoo, Komoot, Strava or any other app that reads GPX.
How should I prepare for Marathon du Lac du Der?
Preparation for Marathon du Lac du Der should account for 42.2 km, 269 m of elevation gain, current training load, and available training time. An adaptive plan helps place key sessions without ignoring recovery and real life.
What pacing strategy works for Marathon du Lac du Der?
The pacing strategy for Marathon du Lac du Der should reflect 42.2 km, 269 m of elevation gain, and your current fitness. Start controlled and keep margin for sections where the profile or fatigue makes target pace harder.
When does Marathon du Lac du Der take place?
Marathon du Lac du Der takes place on June 13, 2027.
Where does Marathon du Lac du Der take place?
Marathon du Lac du Der takes place in Saint-Dizier, France.
Which distances does Marathon du Lac du Der offer?
Marathon du Lac du Der offers 3 distances — Marathon Solo: 42.2 km; Marathon Duo: 42.2 km; Marathon Quatuor: 42.2 km.
How do I register for Marathon du Lac du Der?
Registration runs through the organiser: marathondulacduder.com. YOUB shows you the course, elevation profile and training plan for your preparation.
