This is the first in a series of articles aimed towards runners hoping to complete the Dorset ONER in Summer 2026. Given the overabundance of conflicting, confusing (and often AI written) advice on preparing for ultra-marathons, I will provide well-researched information about training, fuelling, logistics, injury prevention, fundraising, race-plans and equipment. I will provide references where I can, and highlight where information is born out of my own experience or from the experiences of those more qualified. For now, let us focus on the race itself.
The Dorset ONER grew out of an already popular event, the Jurassic Coast Challenge (JCC), which comprises of 3 trail marathons over 3 days, covering the entire coastline of Dorset. It follows the Dorset Coastal Trail, a well-maintained path and public right of way. In around 2007, a competitor asked the organisers if they could do the JCC in one go or "in a one-er". The organisers agreed, and thus the ONER was born.
The event is now known as Rab's Ultramarathon, in memory of WO2 Rab McAvoy, who tragically died by suicide in 2019 following a battle with PTSD. Rab was an outstanding soldier, who's enthusiasm for running (and life) was infectious. Whilst serving in Bovington, Dorset (which incidentally lies along the most challenging section of the route) Rab tirelessly promoted ultra-running; completing the ONER in 2017 with a time of 21:27. He is largely responsible for the enthusiasm for the sport that exists within the Garrison today.
Many of the greatest soldiers develop a catch-phrase, and Rab was known for his saying "Don't be shit!". This may seem harsh and unsupportive to outsiders, but it was said with warmth, humour, and a genuine desire to get the best out of those around him. As a final wink to Rab, the Bovington Garrison's team name will be "DON'T BE SH1T", so look out for the t-shirts!
I urge any readers of this to help me raise money for Combat Stress, either by joining the fundraising team (for runners), or by donating.
Over the years the route of the ONER has changed a little (often due to coastal erosion), but it is generally around 135 kilometres. It runs from Charmouth to Studland, or sometimes Studland to Charmouth, and includes a lap of Portland. Water and food will be provided every 12-15km by the organisers (this year it is Epic Endurance Evets), and they will also ensure the necessary medical support is available. For safety, they will provide a level of tracking technology, which (importantly) can be accessed remotely, so that friends and family can follow along at home. Their other safety responsibilities include checking the route in advance and publishing last-minute changes, ensuring the weather is within accepted limits (in 2024 we had a major last-minute route change due to Storm Kathleen). They will also mandate a suitable kit-list, which they will check at registration.
As mentioned, the race is around 135 kilometres, with the vast majority being along trails, which will also include a mix of mud, grass and rocks. There is around 15km of running along roads, and 3km of "running" along the shingle of Chesil beach. Despite the distance, there is not an excessive amount of ascent (around 4000m), and though the hills are many in number, none of them are higher than Golden Cap Hill at 191m. For safety, there is a 24 hour cut-off which ensures struggling runners do not trudge on headless into injury. Traditionally - only half the runners that enter the race will finish within the time-limit.
On the day of the race, runners will register, receive briefs and conduct kit-checks at Portland, before moving down to the race-start point at Charmouth. After some last-minute admin (photographs and a nervous wee) there will be a mass-start at noon, straight up the first hill.
The route is not marshalled, though it is easily followed, especially with modern smart-watches; as the organisers provide an up-to-date GPX file that can be pre-loaded onto your device. The 1200 start-time means that much of the run will take place in the dark which poses a minor challenge for navigation and staying upright, and a major challenge for morale.
All-in-all it is a tough event, and one of the most challenging endurance races in the UK. I ran it in 2024, with the goal of learning enough about training and my own physiology to adequately prepare for it, and the stretch goal of completing it within the 24hr time-limit. My goal was conservative as I had never run anything like this before (I ran my 3rd, 4th and 5th ever marathon distances consecutively during the race) and therefore my intent was to learn and prepare, and not to win. Despite the complete lack of experience and low-level of baseline fitness when agreeing to this challenge, I finished 9th overall, and well inside 20 hours. I hope that by setting down some of what I learned, I can help other runners (especially first-timers) have as brilliant an experience as I did last year.
Just remember – Run until you can’t run any further. Then keep on running!
