Marathon Eryri 2026: How to Prepare for the Snowdonia Marathon

Marathon Eryri 2026, the road race many runners still call the Snowdonia Marathon, takes place on Saturday 24 October 2026, starting at 10.30am just outside Llanberis and finishing on Llanberis High Street. To prepare well, practise hills, plan to pace by effort rather than by your watch, and pack for wet, windy Welsh weather, because the organiser's own race profile shows 2,748ft of climbing packed into three main climbs.

This guide covers the course in plain words, how to pace the climbs and descents, what to wear in late October, a day-by-day plan for the final two weeks and how to get to Llanberis. Race facts come from the organiser's published information at the time of writing. Edge is not affiliated with Marathon Eryri or its organisers, so always check the official race website and your race emails for the latest details.

When is Marathon Eryri 2026, and is it the same as the Snowdonia Marathon?

Yes, it is the same race with a newer name. The event began in 1982 as the Snowdonia Marathon and became Marathon Eryri in 2023. The 2026 race is the 42nd edition and runs on Saturday 24 October 2026 with a 10.30am start. The organiser says almost 3,000 runners will take part this year.

Do not confuse it with the Snowdonia Trail Marathon, which is a separate summer trail event with a different organiser that also uses Llanberis as its base. Marathon Eryri is mostly on road, loops around Snowdon (Yr Wyddfa) and is famous for its hills rather than its terrain.

Entry was by ballot, and the official website says the 2026 ballot is now closed. If you have a place, the rest of this guide is for you. If you missed out, the 2026 ballot opened in December 2025, so it is worth watching the official site around the same time of year for the next edition.

What are the hills like on the Marathon Eryri course?

In plain words: one big climb early, a long run mostly downhill through the middle, a smaller climb after halfway and a hard final climb near the end. The organiser's race profile puts the total climb at 2,748ft (roughly 840m), an average of 105ft of climbing per mile, and gives a flat-equivalent distance of 29.32 miles. In other words, expect it to feel closer to 29 miles than 26.2.

Mile ranges are rounded from the organiser's race profile chart, so treat them as a rough guide. Check the official course map before race day.

There is no overall course time limit, but the organiser sets a cut-off of 4.30pm (six hours after the start) at Ysgol Waunfawr, at mile 22. That comes before the final climb, so if you expect to be close to it, plan your pacing around reaching Waunfawr comfortably in time.

How should you pace a hilly marathon like Marathon Eryri?

Pace by effort, not by minutes per mile. On a course with this much climbing, your watch pace will swing all over the place, and chasing an even pace up the Llanberis Pass is one of the quickest ways to ruin your last 10km. A simple rule is to keep the effort roughly the same whether you are going up, down or along the flat, and accept that your pace will change.

• Miles 0 to 4.5: hold back. You should be able to speak in full sentences on the first climb. If you are breathing hard at Pen y Pass, you started too fast.
• The descents: lean very slightly forward, keep your feet under your hips and take quick, short steps rather than braking with long strides. Our guide to downhill running technique has simple drills you can practise in the next fortnight.
• Miles 7 to 22: this is the most runnable part of the course. Settle into a steady rhythm, eat and drink early, and treat the climb after Beddgelert as a hill to manage, not to race.
• Miles 22 to 24.5: expect to slow right down on the climb to Bwlch y Groes, and plenty of runners walk sections of it. Purposeful walking with your hands pushing on your thighs can be almost as quick as a shuffle, for less effort.
• The final descent: it is steep. Stay relaxed and let gravity help, but keep control, because tired legs and a fast downhill are a tricky mix.

Set your goal from effort, not from your flat marathon best. Many runners finish Marathon Eryri well outside their road personal best, and that is normal on a course this hilly. Your long runs and hill sessions on hilly routes are a better guide to race day than any flat-road prediction. For building climbing strength over a whole training block, see our hill training guide for runners.

What fuel and drinks are on the Marathon Eryri course?

The organiser lists 12 feed stations, with water at every one. An electrolyte and energy drink is available at miles 6.5, 11, 13, 15, 16.5, 18, 20 and 22, and gels at miles 6.5, 18 and 22. If you have not trained with the drink or gels on offer, carry your own and use what your stomach already knows.

A common approach is to take in some carbohydrate every 30 to 45 minutes from early in the race, but stick with what you have practised. It is also worth planning a gel or drink at Waunfawr, around mile 22. The climb to Bwlch y Groes arrives when energy tends to be lowest, and a little fuel before it starts may make the final miles feel more manageable.

What should you wear for Welsh weather in late October?

The organiser warns that the weather at this time of year can be quite challenging and advises runners to carry some sort of body cover while running. High points like the Llanberis Pass and Bwlch y Groes can feel windier and colder than the valleys, and rain is always possible in Eryri in autumn, so plan for a wet, cool day and be pleased if it turns out kinder.

• A lightweight, packable waterproof jacket you can tie round your waist or stuff into a pocket or running belt.
• Thin gloves and a hat or neck tube that are easy to remove and stash as you warm up on the climbs.
• A short or long-sleeved top to suit the forecast. Overheating on the climbs is as much of a problem as getting cold on the descents.
• Road shoes with decent grip. The course is mostly tarmac, but there is about 2km of farm track and a short unsurfaced section near Bwlch y Groes, which may be wet.
• Anti-chafe balm on your feet, thighs and anywhere straps rub, because wet kit chafes more.
• Your own safety pins. The organiser says it does not supply pins at the event, although race clips are on sale at registration.
• A warm, dry change of clothes for after the finish. There is baggage storage in the registration area.

Wear nothing new on race day. Test your full outfit, including taking the jacket on and off while moving, on your last longer run.

What should the final two weeks before Marathon Eryri look like?

With the race on Saturday 24 October, your final fortnight starts this weekend. The aim now is to arrive fresh, not fitter. You cannot add much fitness in two weeks, but you can easily add tiredness. The table below is a simple example for a runner who has been training four or five days a week. If your own plan or coach says something different, follow that instead.

Two other priorities: sleep well across the whole fortnight, not just the night before, and gradually increase your carbohydrate in the last two to three days. Our guide to tapering for a marathon explains why cutting volume while keeping a little intensity tends to work well for most runners.

How do you get to Llanberis for Marathon Eryri?

Llanberis sits at the foot of the Llanberis Pass in north Wales. The organiser gives these distances: 66 miles from Chester, 103 miles from Manchester and 270 miles from London.

• By car: follow the A55 west along the north Wales coast and take the Llanberis turn-off at junction 11, then the A5 and the A4244. From the Midlands, the organiser suggests the A5 from the M54, and from the south, the A470. There are several pay and display car parks around the village, all within walking distance of registration, and the organiser encourages lift sharing.
• By train and bus: the nearest station is Bangor, and the organiser says there are frequent buses from Bangor and from Caernarfon to Llanberis. Check timetables for a Friday or early Saturday arrival before you book.
• By air or ferry: the nearest airports are Liverpool and Manchester, both about two hours away by car, and ferries from Ireland arrive into Holyhead.

Road closures matter on race morning. The organiser lists a rolling closure of the Llanberis Pass from 9.30am until about 11.30am and part of Llanberis High Street closed from 7am to 6pm, plus further closures and a one-way system around Beddgelert and Waunfawr. Arrive early, park once and walk. Places to stay in and around Llanberis are likely to be busy on race weekend, so book soon if you have not already.

One small bonus for the trip home: the clocks go back an hour in the early hours of Sunday 25 October, the night after the race, so you get an extra hour in bed.

What happens at registration and after the finish?

Registration and the event centre are in the car park area of the former Electric Mountain Visitor Centre in Llanberis. It is open from midday until 10pm on Friday 23 October and again from 7am until 10am on Saturday 24 October, and this is where you collect your race pack. The organiser says the start, just outside the village on the A4086, is only about 10 minutes from race HQ, so there is no bag transfer. Instead, there is baggage storage at registration.

Every runner gets a race T-shirt at registration, and finishers get a slate coaster and refreshments at the finish. The organiser says results go online by early Saturday evening, and runners who give a mobile number are texted their time shortly after finishing. Supporters are welcome, but the organiser notes that the geography makes it hard to cheer at many points on the course, so friends and family may find the finish area in Llanberis the easiest place to see you.

How can you train for hills like these next time?

If Marathon Eryri inspires you to come back stronger, the biggest wins are regular hill running, long runs on hilly routes and strength work for your thighs, calves and glutes so your legs cope with long descents. Edge builds running, strength, HIIT and mobility into one fully personalised plan, so your hill sessions and strength work sit in the same week instead of competing for it, and you can message a real coach anytime if you want help planning around a race like this one.

This article is general guidance, not medical advice. If you are new to exercise, returning from injury, pregnant, or managing a health condition, speak to your GP before starting, and see a physio for any niggle that does not settle.