Yr Wyddfa Ultra.
The 100-mile Yr Wyddfa Ultra sets two jobs back to back: first the steep climbs of Snowdonia, up to around 1,000 metres, then, after passing back through Betws-y-Coed, more than 90 further kilometres by way of Ffestiniog and Beddgelert. Preparing for it means preparing for the moment you leave that village a second time.
Yr Wyddfa Ultra 2027: Course, Elevation & Route Profile
The loop starts in Betws-y-Coed and takes its hardest climbing early. Past the Gwern Gof Isaf checkpoint, the first long ascent begins at km 15 and gains nearly 470 metres. From the checkpoint by the Pen-y-Gwryd hotel a double climb starts at km 22 and tops out around 1,000 metres, and km 36 brings the hardest ascent of the race, about 700 metres of gain. The course then drops to Pont Pen-y-Benglog and runs past Llyn Crafnant back down to the valley.
At km 72 you cross the Village Green in Betws-y-Coed, where the 50-mile race ends. Your second race starts here: through Penmachno to Ffestiniog, on to Croesor and down to Beddgelert, barely above sea level. The Nant Gwynant valley then takes you past Sygun Copper Mine, Llyn Dinas and Llyn Gwynant. From km 135 the route gains another 300 metres and more before returning via Dolwyddelan to Betws-y-Coed.
The race sits in Snowdonia Eryri National Park and the field is capped at 175 places. Eleven checkpoints break up the route, from the village halls of Penmachno, Ffestiniog and Beddgelert to the car parks at Llyn Crafnant and Croesor. For severe weather the organiser keeps a lower alternative route ready.
| Start | Length | Ø | Max. | Gain | Cat. |
|---|---|---|---|---|---|
| km 15 | 2.9 km | 16.3 % | 49.1 % | +468 m | Cat. 2 |
| km 22.1 | 2.2 km | 12.6 % | 31.1 % | +273 m | Cat. 3 |
| km 24.5 | 3.4 km | 14.2 % | 44.6 % | +486 m | Cat. 2 |
| km 35.9 | 4.3 km | 16.7 % | 39.8 % | +709 m | Cat. 1 |
| km 80.6 | 1.9 km | 7.4 % | 15.6 % | +140 m | Cat. 4 |
| km 85.7 | 1.8 km | 12.1 % | 27.1 % | +214 m | Cat. 3 |
| km 113.1 | 1.7 km | 11.3 % | 24.8 % | +186 m | Cat. 3 |
| km 134.9 | 1.8 km | 16.7 % | 33.4 % | +304 m | Cat. 3 |
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 Yr Wyddfa Ultra.
Start under control
The first 46 km hold four climbs totalling more than 1,900 metres, and this is where you can lose the most without noticing. At average gradients between 12 and 17 percent these are walking sections, so walk them from the start at a pace you could repeat at km 135. The descents between them cost the quads just as much, and if you let them run you pay for it later, in the south.
Hold your rhythm
The race turns on the section beyond Betws-y-Coed. At km 72 you stand where others finish, with more than half the distance still ahead. Keep that stop as short as any other. Penmachno to Ffestiniog then runs for over 21 km with a climb of more than 200 metres in it, and that is where you find out whether you have eaten enough so far.
Spend what is left
The last trap lies after Beddgelert. The nearly flat valley floor invites a pace that gets expensive this late, because km 135 brings a climb averaging almost 17 percent. Save something for it, so the final 19 km from Dolwyddelan can still be run.
Training plan for Yr Wyddfa Ultra: 12-week build
Build the base
Age-group athletes should expect roughly 34 to 46 hours out here, so at least one full night is part of the race. The effort stays aerobic almost throughout: brisk walking uphill, running on the rolling sections, hardly any real spikes. What counts is less your output at any one point than being able to eat and move cleanly after 30 hours.
Train race pace
Build the early block with long mountain days: several climbs of 400 to 700 metres in one outing, walked on slopes of 15 percent and steeper, each followed by a descent at running pace. The descent is not an extra. Around a sixth of the course drops steeply, and what that does to your quads decides how the flatter kilometres after Betws-y-Coed go.
Rehearse the course
The second half asks for fatigue resistance more than climbing strength. Two long days in a row, the second on rolling ground with a steep climb near the end, come closest to the section from km 72 onwards. Put at least one long session into the night, so head torch, food and tiredness have been rehearsed together before race day.
Arrive fresh
An early September date does not change the fact that the organiser keeps a separate severe-weather route for these mountains. Test clothing and food in wet and cold conditions as well, and know both routes before you reach the start line. One long session in the rain tells you more about your kit than any fair-weather rehearsal.
Courses
Download the Yr Wyddfa Ultra course as a GPX file for your watch or bike computer.
Let YOUB adapt your plan for Yr Wyddfa Ultra 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 Yr Wyddfa Ultra.
How long is Yr Wyddfa Ultra?
Yr Wyddfa Ultra is 164.15 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 Yr Wyddfa Ultra have?
Yr Wyddfa Ultra has around 5,843 m of elevation gain over 164.15 km. That affects pacing, muscular load, and preparation for late-race sections.
What is the route profile of Yr Wyddfa Ultra?
Yr Wyddfa Ultra is classified as Mountainous, averaging 36.8 vertical metres per kilometre. 13% of the route is flat, 28% climbs moderately (2 to 6%) and 16% is steeper than 6%.
What climbs does Yr Wyddfa Ultra have?
The hardest climb of Yr Wyddfa Ultra starts at kilometre 35.9, runs for 4.3 km at an average of 16.7% and gains 709 metres. Cycling-convention rating: Cat. 1. 8 climbs are mapped in total.
Is Yr Wyddfa Ultra a loop course?
Yes, Yr Wyddfa Ultra is laid out as a loop: start and finish are in the same place.
Is there a GPX file for the Yr Wyddfa Ultra course?
Yes. The Yr Wyddfa Ultra 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 Yr Wyddfa Ultra?
Preparation for Yr Wyddfa Ultra should account for 164.15 km, 5,843 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 Yr Wyddfa Ultra?
The pacing strategy for Yr Wyddfa Ultra should reflect 164.15 km, 5,843 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 Yr Wyddfa Ultra take place?
Yr Wyddfa Ultra takes place on September 4, 2027.
Where does Yr Wyddfa Ultra take place?
Yr Wyddfa Ultra takes place in Betws-y-Coed, United Kingdom.
Which distances does Yr Wyddfa Ultra offer?
Yr Wyddfa Ultra offers 2 distances — Yr Wyddfa Ultra 100 Mile: 164.15 km; Yr Wyddfa Ultra 50 Mile: 72.42 km.
How do I register for Yr Wyddfa Ultra?
Registration runs through the organiser: gbultras.com. YOUB shows you the course, elevation profile and training plan for your preparation.
