Radyr Trail Marathon.
The half at the Radyr Trail Marathon leaves the Welsh capital for woodland and forest and packs just over 640 metres of climbing into 13.6 miles. It is fully marked, so your attention stays on three blocks of hills and a flat run-in through a nature reserve rather than on finding the way.
Radyr Trail Marathon 2027: Course, Elevation & Route Profile
The course kicks up barely half a kilometre in and lifts you to nearly 100 metres. A quieter stretch follows, then just past kilometre four a brief, very steep ramp with passages above 20 percent opens the last part of the first block. It tops out around 170 metres, and by kilometre eight you have handed almost all of that height back.
Then comes the core of the race: two climbs with a short break between them, close to 240 metres together, taking you from about 85 metres to just under 300. That is the high point of the day, and straight after it the trail drops almost to valley level in around two and a half kilometres. The third block from kilometre 14 is smaller at a little over 130 metres, but it arrives on tired legs and has steep sections of its own.
The character of the race lies in the contrast: mountain views, woodland and forest through the middle, then a flat nature reserve where the last two kilometres or so barely rise at all. The race is part of the Radyr and Morganstown Festival, and proceeds go to local charities.
| Start | Length | Ø | Max. | Gain | Cat. |
|---|---|---|---|---|---|
| km 0.7 | 1.1 km | 6.3 % | 13.1 % | +68 m | — |
| km 4.5 | 0.6 km | 11.1 % | 28.6 % | +67 m | — |
| km 5.3 | 0.9 km | 4.4 % | 8.2 % | +38 m | — |
| km 8.2 | 1.4 km | 9 % | 21 % | +126 m | Cat. 4 |
| km 9.7 | 1.2 km | 9.5 % | 14.2 % | +111 m | Cat. 4 |
| km 14.4 | 0.6 km | 5.8 % | 12.6 % | +36 m | — |
| km 15.3 | 1.2 km | 8 % | 20.7 % | +98 m | Cat. 4 |
| km 19.4 | 0.4 km | 7 % | 12.9 % | +25 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 Radyr Trail Marathon.
Start under control
About a quarter of the course is steep and only a little over a fifth is flat, so there is no steady pace to hold here. Race by effort and treat the first block as a warm-up: the ramp after kilometre four is over within a few hundred metres, and a strong hike there costs little time while saving your legs for later.
Hold your rhythm
The race is decided between kilometre eight and the bottom of the descent that follows. Spread your effort across the two climbs so that you can still run at the top, then let the downhill roll under control. Attack that long drop and you gain a few minutes, then pay for them in the third block on quads that no longer hold you.
Spend what is left
The trap is the high point itself. From up there the race feels nearly done, yet around ten kilometres and another serious climb remain. The flat finish in the nature reserve is only a gift if you still have a running stride left when you reach it.
Training plan for Radyr Trail Marathon: 12-week build
Build the base
Expect roughly 2:30 to 3:30 hours depending on fitness. The constant switch between steep ramps and quick descents makes this an aerobic run full of short hard spikes rather than a steady effort, and your muscles suffer at least as much as your endurance.
Train race pace
The core of your preparation is the long hilly run. Build it to two to two and a half hours with around 500 metres of climbing and put the biggest hills in the middle third, where the race puts them. Uphill repeats of eight to twelve minutes match the two key climbs most closely, done in pairs with a short break so that the second one lands on legs that are already working.
Rehearse the course
Downhill running matters just as much. The drop from the high point loses more than 250 metres in one go, and another climb still follows it. Practise longer descents in woodland when you are already tired, and add strong hiking on steep ground, because beyond 20 percent that is the faster way up for most runners.
Arrive fresh
Finish some hilly runs with two flat kilometres at race effort to rehearse the run-in through the nature reserve. Two checkpoints offer water and light refreshments, so test in training what you can stomach and whether two stops are enough or you want to carry something yourself. With the course fully marked, you can leave navigation practice to the marathon runners.
Courses
Download the Radyr Trail Marathon course as a GPX file for your watch or bike computer.
Let YOUB adapt your plan for Radyr Trail Marathon dynamically
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Everything about Radyr Trail Marathon.
How long is Radyr Trail Marathon?
Radyr Trail Marathon is 21.89 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 Radyr Trail Marathon have?
Radyr Trail Marathon has around 641 m of elevation gain over 21.89 km. That affects pacing, muscular load, and preparation for late-race sections.
What is the route profile of Radyr Trail Marathon?
Radyr Trail Marathon is classified as Hilly, averaging 27.5 vertical metres per kilometre. 22% of the route is flat, 26% climbs moderately (2 to 6%) and 14% is steeper than 6%.
What climbs does Radyr Trail Marathon have?
The hardest climb of Radyr Trail Marathon starts at kilometre 8.2, runs for 1.4 km at an average of 9% and gains 126 metres. Cycling-convention rating: Cat. 4. 8 climbs are mapped in total.
Is Radyr Trail Marathon a loop course?
Yes, Radyr Trail Marathon is laid out as a loop: start and finish are in the same place.
Is there a GPX file for the Radyr Trail Marathon course?
Yes. The Radyr Trail 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 Radyr Trail Marathon?
Preparation for Radyr Trail Marathon should account for 21.89 km, 641 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 Radyr Trail Marathon?
The pacing strategy for Radyr Trail Marathon should reflect 21.89 km, 641 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 Radyr Trail Marathon take place?
Radyr Trail Marathon takes place on May 8, 2027.
Where does Radyr Trail Marathon take place?
Radyr Trail Marathon takes place in Tongwynlais, United Kingdom.
Which distances does Radyr Trail Marathon offer?
Radyr Trail Marathon offers 2 distances — Half Marathon: 21.89 km; Marathon: 42.33 km.
How do I register for Radyr Trail Marathon?
Registration runs through the organiser: ridgerunners.co.uk. YOUB shows you the course, elevation profile and training plan for your preparation.
