Leiden Marathon.
The 42 van SWIS is the marathon distance at the Leiden Marathon. It starts on the Koninginnelaan at the edge of the old town, swings out in a wide arc through the polders along the Oude Rijn and finishes under the arch on the Vismarkt, behind the city hall right by the water. What you prepare for here is not a climb but the ability to hold one single pace for hours.
Leiden Marathon 2027: Course, Route Profile & Map
The course leaves Leiden to the south and east and is out of town within a few kilometres. Past the Rijneke Boulevard near Zoeterwoude it reaches the Oude Rijn and follows it to Koudekerk aan den Rijn, running straight through the Dorpsstraat there. This is the loneliest part of the race: dead straight dyke roads, open pasture, little for the mind to hold on to.
The second section turns north through Hoogmade and the small church at the Does towards Roelofarendsveen, where the water tower on the Noordeinde is the only landmark for miles. Only at Leiderdorp does the route come back into built-up ground, crossing the Rhine again at the Spanjaardsbrug and running into town along the Lage Rijndijk.
The last five kilometres are why many people run this marathon. The course follows the ring of canals over Herensingel, Kooilaan, Maresingel and Rijnsburgersingel, turns into the centre at the Stationsplein and the Morspoort and comes onto the Vismarkt via Kort Rapenburg and the Boommarkt. The organizer puts around twenty bands along the route and in the old centre the crowd stands deep. There is effectively no climbing: the whole loop sits in a band of a few metres around sea level, and the only ups and downs are bridges and dyke ramps.
| Start | Length | Ø | Max. | Gain | Cat. |
|---|
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 Leiden Marathon.
Start under control
On a course without a climb there is no natural break and no point where the pace drops by itself. That is what makes the allocation hard: the rhythm you pick in the first ten kilometres is the one you run to the finish. Set it deliberately lower than it feels right at the start and leave it untouched through the polder sections.
Hold your rhythm
The race is decided between Koudekerk and Roelofarendsveen, roughly from kilometre 18 to 32. That is where the course is most exposed, where spectators are thin on the ground and where the wind over open pasture hits unbroken. Running it alone costs pace without you noticing. Find a group early and stay in it, even if it runs a few seconds per kilometre slower than your plan.
Spend what is left
The trap is the finale. From Leiderdorp on it gets narrow, loud and twisty, the canal ring has tight bridges and constant changes of direction, and the crowd lifts the pace. Racing the last five kilometres like a 10K is paid for on the cobbles of the old centre. Take the corners short and keep the tension out of your shoulders.
Training plan for Leiden Marathon: 12-week build
Build the base
For most age-group runners this marathon means three to five hours of work, with a six hour cutoff. The demand is as uniform as a marathon gets: no climb, no descent, no technical section, the same low aerobic band and the same cadence over the whole distance.
Train race pace
That uniformity is the real requirement. When nothing loads the muscles differently along the way, the same structures fatigue throughout, and the last ten kilometres become a question of muscular durability rather than endurance. Long runs of two and a half to three hours on flat asphalt with a quicker closing section reproduce exactly that.
Rehearse the course
The decisive phase, the open polder stretch in the middle of the race, asks for two things. First, long blocks at marathon pace, for instance three times five or two times eight kilometres at goal pace inside a long run. Second, the ability to run into wind without lifting the effort: train deliberately on open ground on windy days and learn to shelter in a group.
Arrive fresh
Early May in the Netherlands delivers anything from cool rain to the first warm days of the year, and the course offers no shade at all. Fix your fuelling to kilometre marks rather than to feel, rehearse it in the long runs, and choose your kit for wind rather than for temperature.
Courses
Download the Leiden Marathon course as a GPX file for your watch or bike computer.
Let YOUB adapt your plan for Leiden Marathon 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 Leiden Marathon.
How long is Leiden Marathon?
Leiden Marathon 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 Leiden Marathon have?
Leiden Marathon has around 58 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 Leiden Marathon?
Leiden Marathon is classified as Flat, averaging 1.4 vertical metres per kilometre. 93% of the route is flat, 3% climbs moderately (2 to 6%) and 0% is steeper than 6%.
Is Leiden Marathon a loop course?
Yes, Leiden Marathon is laid out as a loop: start and finish are in the same place.
Is there a GPX file for the Leiden Marathon course?
Yes. The Leiden Marathon 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 Leiden Marathon?
Preparation for Leiden Marathon should account for 42.2 km, 58 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 Leiden Marathon?
The pacing strategy for Leiden Marathon should reflect 42.2 km, 58 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 Leiden Marathon take place?
Leiden Marathon takes place on May 9, 2027.
Where does Leiden Marathon take place?
Leiden Marathon takes place in Leiden, Netherlands.
Which distances does Leiden Marathon offer?
Leiden Marathon offers 4 distances — 42 van SWIS: 42.2 km (Marathon); 21 van Bunnig & Partners: 21.1 km (Half marathon); 10 van Zorg en Zekerheid: 10 km; 5 van PF Concept (Nightrun): 5 km.
How do I register for Leiden Marathon?
Registration runs through the organiser: marathon.nl. YOUB shows you the course, elevation profile and training plan for your preparation.
