My marathons

20 van Alphen

March, day not yet published Alphen aan den Rijn
Alphen aan den Rijn
© OpenStreetMap Alphen aan den Rijn. Photograph by Michielverbeek, CC BY-SA 4.0 via Wikimedia Commons . Course line © OpenStreetMap contributors

The course

Drag along the profile

Flat from start to finish: 7 m between the lowest and the highest point.

StartFinish

© OpenStreetMap contributors

Height drawn many times taller than life. Heights: GEDTM30.

Course elevation profile, 8× vertical exaggeration Elevation along the course from km 0 to km 21. The trace runs between -2 and 5 metres, a range of 7 metres, drawn at 8 times vertical exaggeration so the shape is legible. Smoothed over 1 km before this profile was derived. An unsmoothed urban surface carries the buildings and would assert a climb that is not there. The dashed stretches are bridge decks: Willem de Zwijgerlaan, km 0.7 to 0.9; Willem de Zwijgerlaan, km 12.1 to 12.3; Alphense Brug, km 20.6 to 20.6. A bare-earth model reads the ground or the water beneath a bridge, not the deck the runner is on, so those runs are interpolated between the ground either side rather than measured, and they under-report the real climb across a span.
0 5 10 15 20 km
0 5 10 13.1 mi

Dashed: bridge

  • flat all the way

Your 2 gels, at the orange marksFor a 1:55 finish, one every 40 minutes

  1. km 7.3mile 4.6
  2. km 14.7mile 9.1

Get them on AmazonAmazon partner link

The course in short 3 lines
  • A half marathon between 2.3 m below and 4.7 m above sea levelBetween -2.3 m and 4.7 m, 17.1 m of climbing in all.
  • Two different laps of about 10 km, on paved roadsTwo different 10 km laps, start Prins Bernardlaan, finish Burgemeester Visserpark.
  • A 3:15 limit and a halfway gate in 20262026: 3:15 limit, 11 km point by 14:00, finish closed at 15:45.
Course notes 3 short reads on the course
km 0 to 21.1GradientA half marathon between 2.3 m below and 4.7 m above sea levelBetween -2.3 m and 4.7 m, 17.1 m of climbing in all.

The lowest point is 2.3 m below sea level at 15.0 km and the highest is 4.7 m, at the finish in the Burgemeester Visserpark.

Measured

km 0 to 21.1GeometryTwo different laps of about 10 km, on paved roadsTwo different 10 km laps, start Prins Bernardlaan, finish Burgemeester Visserpark.

The Dutch Athletics Union (Atletiekunie) measured the half marathon course and certified it in February 2026. The 60th edition is on 6 and 7 March 2027.

Sourced

km 11 to 21.1FinishA 3:15 limit and a halfway gate in 20262026: 3:15 limit, 11 km point by 14:00, finish closed at 15:45.

The 2026 half marathon started at 12:30 on Sunday 1 March, together with the Rabobank Businessloop half marathon.

Sourced

Race fuel

Energy gel
An energy gel sachet
Illustration · drag to turn

2 gels for Alphen aan den Rijn, plus 1 spare

Finish

One every 40 minutes, the orange marks on the profile. Alphen aan den Rijn stays within 7 m23 ft of height, so they go by the clock:

  1. km 7.3mile 4.6
  2. km 14.7mile 9.1

Our pick: SiS BETA Fuel gel, box of 6, strawberry and lime. 40 g of carbohydrate a gel, about twice a usual gel, from two kinds of sugar your body takes up side by side.

Easy to forget on race morning: pack them with your bib the night before.

Get it on Amazon

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In Canada the button opens GU Energy Gel, Salted Caramel, 24-pack, the best seller there.

Outside the Netherlands, Belgium, Germany, Austria and Switzerland, the UK and Ireland, Spain and Portugal, Italy, the rest of the EU and Canada the button opens GU Energy Gel, Chocolate Outrage, 24-pack on Amazon.com, the best seller there.

Anti-chafe
Compeed Anti-blister stick
Photo: Compeed

Compeed

Compeed anti-blister stick, 8 ml

Best selling on Amazon amazon.nl, read 2 Nov

An invisible layer before the start keeps seams, straps and shoes from rubbing skin raw.

Put it on before you leave for the start: heels and toes, inner thighs, under a bra or heart-rate strap.

Try it on a long run first, like everything you use on race day.

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We earn a small fee if you buy through these links. The price is the same.

Number belt
A race number belt
Illustration · drag to turn

Compressport Race Belt

Holds your bib without safety pins through your top, with loops for up to 8 gels.

Clip the bib on the night before, so it goes on with your shorts in the morning.

Keep the number on the front, where officials and photographers can see it.

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We earn a small fee if you buy through these links. The price is the same.

Electrolytes
A tube of electrolyte tablets
Illustration · drag to turn

SiS Hydro electrolyte tablets, tube of 20

One tablet in a bottle puts back some of the salt you sweat out.

One tablet in 500 ml of water in the hour before the start.

Only if you have used them in training: nothing new on race day.

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We earn a small fee if you buy through these links. The price is the same.

Blister plasters
Compeed Blister plasters, medium, 6
Photo: Compeed

Compeed

Compeed blister plasters, medium, 6

Best selling on Amazon amazon.nl, read 2 Nov

One in a pocket cushions a blister if one starts.

Put it on clean, dry skin and leave it until it comes off by itself.

Give a couple to whoever comes to cheer, so they are there at the km you need them.

Get it on Amazon

We earn a small fee if you buy through these links. The price is the same.
distance
21.1 km13.1 mi
climb
17.1 m56 ft
cut-off
3:15 h

The 20 van Alphen is a flat course of 21.1 km with 17.1 m of climbing. Its lowest point is 2 m below sea level and its highest 5 m above it.

Trip

Getting a place

Entry through the organiser

Entry details on the organiser’s site →

The organiser, a third party. We take no entries and have no part in the race.

Sources and licence

Last checked.

Course line matched onto OpenStreetMap road geometry: (c) OpenStreetMap contributors, Open Database License 1.0 (ODbL). Elevation sampled from GEDTM30, Global Ensemble Digital Terrain Model at 30 m (v1.2): Elevation: GEDTM30 (Ho & Hengl, OpenGeoHub), CC BY 4.0, Creative Commons Attribution 4.0 International (CC BY 4.0).

Elevation gain computed by us from that line, smoothed over 1 kmsmoothed over 0.6 mi.

The line follows the road down its middle, so it measures 4.08% longer than the certified distance, which is measured on the shortest legal line through every bend.

Date and entry information from the organiser.

Every source and licence behind them →

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