Turning 40 into a mission for St. Jude

Growing up in St. Louis, Scott MacArthur dreaded the 5Ks his father registered his family to run. He often found himself trailing far behind his athletic older sisters and dad, who finished the races well before him. But one hilly 5K in St. Charles, Missouri, was different.

“I was getting ready to quit,” MacArthur said. “But when I was getting ready to throw in the towel, I saw my dad coming back for me to encourage me and say, ‘Hey, you're not giving up. Let's get this done. Your finish line is right around the corner.’ It was a lasting memory for me.”

Years later, his father was diagnosed with cancer and passed away when MacArthur was 13, but his family carried forward his passion for running. MacArthur’s oldest sister ended up running her first marathon in St. Louis at the age of 15, and MacArthur’s other sister would frequently spend weekends running more than 20 miles.

More than two decades later, his dad’s legacy continues. As MacArthur nears his 40th birthday, he is taking on a challenge few athletes ever attempt. He has pledged to complete all eight Abbott World Marathon Majors, a championship series featuring the largest and most renowned marathons in the world, in a single year. And he’s doing it to fundraise for St. Jude Children's Research Hospital®. 

“I wanted to do something impactful. I wanted to do something that I could look back at and say, ‘I did something amazing when I turned 40 years old,’” MacArthur said. 

His fundraising target for St. Jude was $75,000. He was undeterred.

Now halfway through the year-long challenge, MacArthur has run four of the eight major marathons and completed several St. Jude Rock ’n’ Roll Running Series races. “It's been an incredible experience. And it's been eye-opening understanding what the true mission is and what St. Jude does and the level of the impact that St. Jude has on the families and the kids.”

His goal of completing multiple marathons is a sharp contrast to how he felt after finishing his first. As a young professional, MacArthur took up running to stay fit, dreaming of eventually running the Chicago Marathon and even registering for it multiple times.

However, training injuries and inconsistency led him to cancel each registration. 

In 2018, a colleague’s message pushed him to finally commit and run the race — with virtually no preparation. Halfway through, his legs cramped, and he considered quitting. But something made him push on.

“I hit mile 13 and I was ready to quit, when I felt my dad's presence saying, ‘Come on, finish line is right around (the) corner. You got this. You’ve got to keep on going,’” MacArthur said.

When he crossed the finish line, exhausted and in pain, he told himself it would be his first and last marathon. The day, however, had another miraculous surprise in store.

“I typed in my name to see what time I got,” he recalled. “I just typed in MacArthur, my last name. And literally, there were two MacArthurs that ran that race that day. It was me … and then as weird as it is, there was another MacArthur there … my dad's name.”

“It was honestly incredible," he added with a laugh. "I sent it to my whole family like, ‘You will never believe this.’ And we all had goosebumps afterwards.”

MacArthur entered several marathon entry lotteries, but his name was never selected. When the COVID-19 pandemic began, he gave up on signing up for the races. However, in 2021, MacArthur's family was hit with a second family member's diagnosis with cancer, leading him to focus on his health again.

Watching their perseverance through treatment motivated him. “If they can get to that finish line, I can get to that finish line,” he said. In 2022, a familiar London Marathon rejection email arrived with a twist. Although he had been rejected, it introduced him to the option of running a marathon for charity. 

MacArthur agreed and signed up to benefit a UK-based cancer charity. However, the organization had no race bibs left by the time he had reached out in November 2022. They offered MacArthur a spot on their waitlist instead, and he accepted. He assumed that the waitlist was for races in the future.

Then, five weeks before the 2023 London Marathon, he was offered an open spot after another runner was injured.

“I immediately said yes,” MacArthur recalled. 

After a whirlwind of booking flights and hotels, he ran the marathon. The experience left MacArthur determined to complete more of the races and ultimately, he went on to run all 7 Major Marathons between 2023-2025.

Throughout all of the marathons, there was a lasting memory of his first marathon and ultimately, he wanted to redo the Chicago Marathon. Having completed it as his first marathon with little training, he wanted a second chance to do it “the right way."

“I wanted to go redo it and set the record straight. And when I started looking at the charities that were out there for Chicago, I noticed St. Jude on the list.”

In 2025, he ran Chicago on behalf of St. Jude and began to learn more about the research hospital’s mission and impact leading up to the races and beyond.

“Hearing about the true impacts on the families that they're touching and the innovative medical procedures and techniques that are being practiced around the globe, I thought, ‘Whoa, this is a lot more than I thought it was.’ I was very flattered to be running for an organization like that.”

That marathon led to MacArthur’s commitment to run all eight of the Abbott World Marathon Majors for St. Jude. He's raised nearly $100,000, with his own family’s experience of cancer being the backbone that drove him forward. MacArthur is set to cap off his journey in December 2026 at the St. Jude Memphis Marathon® Weekend, completing 9 marathons in the same calendar year and 5 Rock 'n' Roll Half Marathons.  

 Abbott World Majors has published the number of runners that have run all 4 Majors this year so far, and MacArthur is currently sitting in a field of 40 runners globally that are on track to accomplish this feat, which will mark his second six-star medal. 

“People are asking me, ‘After this year, what are you going to do next?’” he said. “And I’ll do something for sure, because this has been a great experience for me to understand more about what St. Jude does. I'll continue to work with St. Jude for my lifetime… the people. heroes, the staff, the patients, families and most importantly the mission is incredible.”