Langdale Marathon Runner

The UK’s Toughest Marathons, Revealed

Up for a challenge this year? We look at the UK's toughest marathons and how you can make sure you're not a DNF statistic!

The 26-mile distance is always a challenge, but some races are tougher than others. Recent research by New Balance explored UK road running races with the highest number of did not finish (DNF runners), and it makes for interesting reading. So if you're looking for a real challenge in 2023, check out any of the UK’s eight toughest marathons.

  1. Langdale Marathon: 15% DNF
  2. ABP Southampton Marathon: 5.30% 
  3. Abingdon Marathon: 4.80% 
  4. Snowdonia Marathon Eryri: 2.50% 
  5. Milton Keynes Marathon: 2.37% 
  6. The Manchester Marathon: 2.05% 
  7. Mash Direct Belfast City Marathon: 1.47%
  8. Asics Windermere Marathon: 0.84%

As you can see, the data revealed that Langdale Marathon is the UK’s toughest with the highest percentage of DNFs. The study found that 15% of runners who entered Langdale failed to finish the race. The race is situated in the heart of the Lake District with runners facing an elevation gain of 1036m, ranging from mild up-and-down-hills, to steep climbs and drops, and no flat terrain.

In second place was the ABP Southampton Marathon, which has a DNF percentage of 5.3% and in third was the Abingdon marathon where 4.8% of runners failed to cross the finish line.

Halfway hurdle takes out over half of those that don’t finish


The research also revealed that over 65% of people who drop out will do so after the halfway point (13.11 miles). After this, the most significant marker for participants dropping out was mile 23. 

Numbers suggest that female runners may be more resilient when it comes close to the finish line, with 16% of men that DNF dropping off just three miles before the finish line compared to 5.4% of women.

Typically, after the halfway point, the human body has used up all the stored carbohydrates and glycogen and begins using fat as energy. The body having depleted all reserves of glycogen instigates feelings of physical and mental exhaustion, this phenomenon is called 'hitting the wall', and it can happen when you enter a race without serious preparation. 

Jonny Mellor, a New Balance marathon runner explains: “There’s a big difference between running a half marathon and a marathon.

"There are a lot of reasons why people can’t get to the finish line. Often, the reason behind it is the lack of energy. If runners aren’t fuelled enough, they can reach the half distance, but after that, they can no longer continue.

“Another reason for not finishing is not respecting the distance. Marathon is a hard race and requires a firm training plan that includes recovery time and resting. Not preparing seriously leads to not finishing.”

But amateurs should not take off their running shoes and be deterred by the possibility of not finishing. In 2022's London Marathon, even a quarter of elite runners did not finish the race. 

Mellor highlights weather conditions and 'hilliness' as crucial factors for success or failure.

Conditions are a huge contributing factor to success or failure

Elevation is not just a toughness factor in Langdale, another national park offers a similar challenge – at Snowdonia Eyri Marathon there is an elevation gain of 933m. Mellor comments: “Whether it’s a hilly course as opposed to a flat one, makes a difference. I was running the Commonwealth Marathon in Birmingham where I had to bear in mind the last 5 kilometers were all uphill. It makes a race harder.”

If a runner has only trained on track and flat road, hills can wear them down physically and mentally. On the way up, more energy is used; and different muscles are worked between going up and down.

When it comes to the weather, according to researchers, a perfect marathon day has temperatures between 10 and 17.5°C. Any temperature that's higher than that declines performance by 0.3% to 0.4%. Wind and heavy rain are also factors which can affect performance.

Image: Brathay Challenges/Jumpy James Photography & Web

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