A former video game world-beater is now on a mission to complete 74 ultra-marathons in 74 days.Sam King was once top of the leaderboard on Call of Duty, one of the biggest gaming franchises that attracts millions of players worldwide.King once weighed around 18 stone and was a Call of Duty expert@fatboysking InstagramHe has undergone an impressive transformation and taken on a huge challenge@fatboysking InstagramHe left his home of Frinton-on-Sea in Essex for the hustle and bustle of London, before an incident earlier in 2025 inspired him to change.King’s mum suffered a bleed on the brain and he’s now ventured into endurance sport to raise money for the charity Headway.Speaking to Hawksbee and Jacobs on talkSPORT, King revealed he is running 31 miles a day in 74 different ultra-marathons and that since leaving gaming, he has lost an incredible amount of weight.“I’ve had sort of three phases of my life,” he explained. “The gaming phase, which was quite intense, no. 1 in the world on Call of Duty. “The weight loss phase that followed, where I lost seven stone in about six months. And then the running phase that I’m now in, so you could say I’ve got an addictive personality! “I’m just now at least applying it to something a little bit healthier, well, some might say a little bit healthier to sitting down and gaming all day behind a screen. King added: “I left home to get a job in London after messing up my entire education from playing computer games. “So I had sort of a lot of pressure on my shoulders to make something of my life without an education or a degree and I moved to London quite overweight, and a bit lost and looking for a job. “I remember looking in the mirror one day and thinking, ‘I think you really need to sort yourself out.’ Part of that was finding a job, part of that was losing weight, so I just immediately decided that was what I was going to focus on. “I just sort of changed my ways, started exercising more, started eating less, started drinking less, or at least drinking differently, like moving to spirits from beer, things like that. It just fell off and within seven months, I’d lost about seven stone.”King is helping to raise money for charity after his mum fell ill earlier this year@fatboysking InstagramRecalling his mum’s incident, King said: “So, January 29 this year, my mum collapsed in my arms, in this house actually at home in Frinton-on-Sea, where I grew up, with a bleed on the brain. “She had been a very, very healthy woman her whole life. She was mid-70s, but as healthy as can be, got her step goal every day, always active, never sat down, never been to hospital, so it was a big, big shock when she collapsed with the bleed on the brain. “We went to hospital that day and were told that she wouldn’t make it through the night, and that we’d sit with her and wait for her to take her last breath. It was the worst day of my life, I absolutely adore my mum, we’re really close, always have been. “The three to fourth months that followed after that, I was seeing mum in hospital, I was working my job in London, I was training for different events, running-wise, and it was just too much, it took its toll on me. “I had a small break in South Africa where I was doing an ultra-marathon, actually, and I decided there and then that I was going to leave my job the week that I got back, and I was going to run an ultra-marathon every day for 74 days.“One for every year of my mum’s life before she fell ill, and to raise money for Headway, the brain injury charity who had helped us through the process of her being really ill in hospital this year.”King has had to battle against injury worries to get through the challenge@fatboysking InstagramHow far through the challenge is King?King has raised close to £38,000 for Headway, who provide support and services to those who have suffered brain injuries.He is almost three quarters of the way through his huge challenge, one that has taken a toll on his physical health.“I’m on day 52 [on Monday], so I’ve made a dent, but it hasn’t been without its challenges. The first two or three weeks, my body was really rejecting what I was doing.“I had quite a few injuries in those first few weeks. I was sleeping really badly, I was ill for a couple of days, and it was very difficult to push through those days. B“But this obviously means a lot to me, what I’m doing, and I managed to get through them. Actually, ever since the first two or three weeks, my body has really adapted into it, I sleep really well and I wake up quite fresh. “It’s incredible, what my body is now, how it has evolved and developed, and got used to what I’m doing. But in the last few days, I did have an all too familiar pain come through my knee, and I’ve only ever had one running injury. “It was a stress fracture in the exact same knee, so that has been very unsettling and yesterday it was particularly bad. “But I’ve been out today, and it wasn’t as bad, which is the trajectory that we want to be on because if it was a bone issue, it probably would persist and get worse constantly. “So I’m hoping it isn’t and I’m hoping I can keep going, but today was a good day.”King has persisted and is on his way to raising £74k for Headway@fatboysking InstagramKing posts daily on Instagram with updates of his challenge, which has seen him make an incredible transformation in his life.He was once of the world’s top gamers but is now pushing his body to the limit to raise money for a cause so close to his heart.Given he was so skilled on the controller, King was asked if he has ever gone back to his Call of Duty days.“No, I haven’t played it for a long time and the last time I tried, I was absolutely terrible at it,” he revealed.“I thought, ‘Right, I’m not even going to go there’, because I don’t like being bad at things, I have to get as good at them as possible, as quickly as possible. “But, there was about six million people on the leaderboard when I was no. 1, and it was 12, 18 hours of my day dedicated to playing it constantly. It was quite exciting, it was a thrill, I loved it. “I’m fiercely competitive, always have been so I really enjoyed the gaming phase, but it was a very unhealthy phase and when I came out of it, I was in a really bad way in terms of mentally, I was really insecure with my body and how big I’d become. “And like I said, I messed up my education so thankfully, I eventually found running and I’ve channeled everything into that, and that’s had a really positive impact on my life. “I did eventually get a job in London and here we are.”