For most people, taking on a marathon is a once-in-a-lifetime bucket-list achievement that sees the running shoes hung up for a well-earned rest soon after.
But remarkable runner Sarah Matthews has just completed the incredible feat of finishing 53 marathons in just 52 weeks.
And her achievement was all the more remarkable as she did it while battling an undiagnosed disability that can leave her unable to walk or talk.
The 39-year-old Widnes Running Club member also completed her 100th marathon along the way for good measure.
Her remarkable odyssey saw her run in New York, Chicago, Philadelphia, Berlin and Niagara Falls - as well as the less famous surroundings of Gravesend and Milton Keynes.
She said: "People had been saying go for 100 marathons and that became 52 in a year. I just thought why put it off? Try and do it because come tomorrow I may not be able to run at all.
"When I told my husband James what I wanted to do, he said I was going to die. But he has been so supportive.
"Now I have done it, I could be sitting in a chair but I'll be doing it in my 100 marathon vest that no-one can take away from me."
Always a keen runner, Sarah, from Warrington, first started to notice the symptoms of her disability six years ago and it has gotten worse since then.
She explained: "I had a lot of tests but they don't really know what it is I have. However it can mean I can't walk or talk for five minutes or five hours.
"I just plan everything out carefully and do everything a lot slower. If I try to multitask my brain explodes so I just do everything one small step at a time as I have to tell my brain everything.
"Like eating with a fork is one step on a good day but it’s 14 steps on a not good day. On really bad days I can’t use a fork at all.
"Running wise crowds can affect me and I can get dizzy too, while loud noises can be disorienting"
Sarah was able to work around her condition throughout her year of marathons, while raising money for the Warrington Disability Partnership - you can donate here.
Her first of the 53 was in Lanzarote in December 2018.
At different times, Sarah did four events in four days, seven in seven and even 10 in 10 days to make up the numbers.
Sarah also travelled in America for a month, running the Chicago 5k and Marathon, Niagara Falls marathon, Marine Corps marathon, New York marathon and Rocky Run 5k and 10 mile.
"America was pretty epic," she said.
"I was travelling alone until New York and it was tough but so amazing. I used to be very hyper doing a billion things an hour, but I was ill a lot so I had to learn to just chill and treat everything I could do as an opportunity.
"Niagara Falls marathon is amazing. You start in the US and cross the border into Canada after five miles. You have to go through border control on the way to the start.
"I was really ill that day but the majority of the race is just on a calm quiet road next to a beautiful river with little pockets of support.
"For the last 5k you can see the spray of the falls and you finish at the top of the Canada falls with rainbows and every thing. It’s so pretty."
Sarah also ran up the famous Rocky steps in Philadelphia after doing the 5K and 10-mile events.
"The Rocky Run was a lot of fun. It’s the only race my husband would do and there were loads dressed up as Rocky - full on shorts, gown and boxing gloves even though it was freezing. They played Rocky music the entire race too.
"I ran up the Rocky steps carrying all my medals. After every marathon I do a stair test. If I can run up and down stairs then I’m good to do the next marathon so they were the ultimate test."
Despite putting her body through such a prolonged ordeal, Sarah said she did not train much for the marathons.
"I think the marathons were training themselves, so i would do one, take a few days and be ready for the next one," she said. "I'm rubbish at training so didn't have a plan.
"It helped as well that I wasn't going for a time, I was just getting round so wasn't pushing myself to race."
While Chicago was her favourite event - "a lovely community feel, even though it's massive" - Sarah didn't enjoy Berlin where she was pushed about a bit and had people constantly checking her bib to see if she was in the right starting pen.
She said: "When people see a runner, they don't always realise the amount of effort it has taken to get there or what battles that person is going through, especially if that person has a disability that is not easy to see.
"Berlin was tough, but I wore a disabled runner vest since then which made a big difference."
Apart from her husband, Sarah had tremendous support from her family - with mum Margaret running part of a race with her. Her friends at Widnes running club were also very encouraging, with close friend Ali Lysons surprising her in one of her final events.
"That was so brilliant of Ali," said Sarah. "When you're in the middle of something like that getting a note saying keep going is a massive help, so seeing her waiting by the start was incredible.
"I could have done with support in my final marathon in Lanzarote. By then I'd done the 52, but I had entered and I started there so decided to do it. Most of the way round I kept thinking 'I could be on the beach' so I did 53 instead of 52.
"It is such a big thing for me to have done it that I'm still coming to terms with, amazing really."
Now her feat is completed, Sarah is taking a break before deciding what to do next, but hopes to help improve the awareness and support systems for disabled runners.
She also had some words of wisdom for anyone contemplating their first marathon.
"Never limit yourself," she said. "If you have a dream then you'll find a way to do it no matter what obstacles come your way."
You can donate to Sarah's chosen charity here and find out more about Widnes Running Club via their website.