11-02-2025
7 marathons, 7 continents, 7 days: Why a cancer surgeon pushed himself to the absolute limit
Clark Gamblin, a cancer surgeon in Milwaukee, doesn't look much like an elite distance runner. He's 55, medium build and bookish, with glasses and specks of grey in his hair. He listens to classic rock and contemporary Christian, reads books about Teddy Roosevelt and spends most of his time thinking about cancers of the liver and bile duct.
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But one day in the spring of 2023, he opened Facebook and saw a message and link from a friend named Mark Russell:
'Let me know when you're ready for this … '
The link sent Gamblin to a website for something called the World Marathon Challenge, an eight-year-old event with a tantalizing tagline:
'Seven Marathons. Seven Continents. Seven Days.'
Looking at his phone, Gamblin had one thought: How could anyone do that?
Gamblin was a dedicated runner but more weekend warrior than certified pro. When he ran the Boston Marathon in 2018, it was his first marathon in 21 years. When he was diagnosed with cancer that same year, he pushed on, finishing five more marathons in the next six years.
He looked at the link again. The details were staggering. As was the $48,000 price tag. Still …
'I couldn't get it out of my head for some reason,' he said.
At the start of each year, millions of people set goals. They resolve to work out longer, read more, drink less. Some people want to run a marathon. Others try to learn a language. According to research by Columbia University, around three-quarters will stop in the first 30 days.
Another fraction, however, will strive for more and discover something about themselves in the process. This is the fraction that includes Clark Gamblin.
'I think far too often we're very careful in our goals,' he said.
Gamblin believes in 'reach goals,' the extraordinary objectives that force us to re-think what is possible. A single marathon was one thing. But seven on seven continents in seven days?
'I saw this as something that I thought would change me,' he said. 'And change me for the better.'
On that day in 2023, he closed the link, exited Facebook and put his phone away. The first marathon would take place Jan. 31, 2025 in Antarctica.
He had 19 months to get ready.
Gamblin has a mantra: The body will do what the mind says it will do.
For years, it applied to his job as a cancer surgeon. He witnessed the power of the human body and the fortitude of the human spirit. He believed in the idea of grit. It took him three application cycles to be accepted to medical school, and when he started treating cancer patients, he always told them they needed three things on their journey: Faith in something, family and friendships.
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One day in 2017, he was sitting in a national board meeting for the American Liver Foundation, an official partner of the Boston Marathon, when someone suggested it would be nice if a board member ran. Gamblin had played football in high school in Mississippi and ran a few marathons during medical school. But for the last 20 years, running had been, at most, a casual pursuit.
As he looked around the room, he didn't see many candidates. Plus, the marathon was scheduled for his 49th birthday, so he took the plunge.
It was a brutal spring day, windy and wet. But when he crossed the finish line after four and a half hours, something clicked. He made plans to run the New York Marathon that fall.
Gamblin spent his summer continuing his training, but one day in August, as he got ready for work, he noticed a mass in the left side of his scrotum. At first, he thought it was a blood vessel malformation called a varicocele. But Gamblin had spent his career telling patients to 'act on abnormalities,' so he called his primary care doctor and told him he needed an ultrasound.
'It's probably nothing,' he said.
It had already been a long summer. That same month, Gamblin had told his three children that he and their mother were divorcing after 21 years of marriage. Now he was at the hospital on an early morning, looking at his own ultrasound.
No, it wasn't a blood vessel malformation.
As a cancer surgeon, Gamblin knew all the stats about testicular cancer — that it's the No. 1 cancer among men ages 14 to 49; that one in 250 men will be affected in their lifetime; that, importantly, it's close to 95 percent curable when detected early.
Gamblin walked over to the hospital's cancer center and found his colleague Peter Langenstroer, a urologist. They scheduled surgery for the next week. Next came a round of chemotherapy, which was supposed to cut the chances of a recurrence down to five percent. The chemo was unpleasant, but one of Gamblin's biggest questions was whether it was safe to run the New York Marathon two months later.
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'You can do it,' his oncologist told him. 'You'll just feel horrible.'
He finished in four hours and 51 minutes.
For months, Gamblin rarely told his patients about his cancer diagnosis.
For one, he didn't want them to think he knew how they felt because 'every cancer journey is different,' he said. He did, however, keep running, turning his focus to completing the 'World Marathon Majors,' the championship-level events that attract dedicated runners from around the globe.
He also heeded a colleague's advice to put himself out there. On the eve of leaving for the Berlin Marathon in 2019, he went on a Bumble date with a school district executive named Jan.
'I'll be the tall guy at the bar with the big smile,' he told her.
He didn't mention cancer, though he did note his new hobby. Maybe they could have a second date when he got back from Berlin, he said. The relationship flourished. When Gamblin's cancer came back in 2020 and required another surgery, they prayed together. Then he kept running.
He and Jan married in the fall of 2022, and when he completed the Tokyo Marathon in 2023, Jan thought their biggest running adventures were over.
But then later that year Gamblin told Jan about the World Marathon Challenge. The event would begin in Antarctica, where he would run a marathon at a base near Novo Runway, then he and around 60 other runners would pile back into a charter jet and run six more. Among her many concerns about his safety, Jan also had a pertinent point.
'You have a day job,' she said.
Another hurdle was the $48,000 entrance fee. An acquaintance who specialized in fundraising suggested he could start a GoFundMe. Gamblin laughed. 'Dude,' he said. 'I'm a doctor. Anyone with half a brain will say: Take two years off, save some money and do it.'
Gamblin found support from Roger Magowitz, a former mattress executive and cancer fundraiser who had lost his daughter Melissa Smith to COVID in 2022 at 34. Magowitz told Gamblin that his daughter had suffered from a genetic liver disease. When he found out that Gamblin treated liver cancer, it seemed like a sign. He pledged $10,000.
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'Take my daughter with you,' he said.
As more corporate backers came in, Gamblin set another goal: He wanted to raise $250,000 for the Testicular Cancer Awareness Foundation. He hired a local running coach to set his training regimen and used an Instagram account to track his progress.
Now all he had to do was train.
On the morning of Dec. 29, Gamblin woke up and went out for a 20-mile run through the cold winter of Wisconsin. The next day, he ran 20 miles again. In a week's span, he ran 102 miles.
Gamblin was never fast. But he is consistent: His splits are almost always negative, meaning he picks up steam as a training run goes on. It happens naturally. His mind calms, his body relaxes and he starts running faster.
On most days, he would start at 4:30 a.m. He listened to Led Zeppelin or AC/DC and devoured audiobooks of memoirs and mysteries. When he thought about his goal all at once — seven marathons in seven days — it felt daunting. But when he broke it down into daily practice, he had a roadmap to follow. He was always a habitual list maker, often writing down things he'd already done just to check them off, but he developed another strategy to stick to his plan. He created a seven-day calendar, filled with life commitments and training runs, and then he revisited it each night, always updating the 'eighth day away.'
'I don't think about what I'm going to do today and tomorrow,' he said. 'I've determined that.'
The process built confidence.
'People are more capable of doing things than they really think they are,' said Chris Pack, a retired U.S. Army First Sergeant and ultramarathoner who helped program Gamblin's runs. 'You can really train the body to be really resilient, and it really does become a mental game.'
The task before him would be grueling. After the first 26.2 miles in Antarctica, Gamblin would run marathons in Cape Town, South Africa; Perth, Australia; Dubai, UAE; Madrid, Spain; Fortaleza, South America; and Miami. His sleep would come during long charter flights. In the decade since the World Marathon Challenge began hauling runners and thrill-seekers around the world, hundreds of people had accomplished the feat. Some were accomplished marathoners. But others were folks like Gamblin, people who just wanted to think bigger.
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One day in January, he thought about a quote he first heard when he was a teenager, a saying inspired by the English poet Robert Browning: 'Play for more than you can afford to lose. Let your reach exceed your grasp, and then you will know the rules.'
Only seven marathons to go.
The first marathon went according to plan. As did the second and the third. His legs felt strong, his mind clear, his spirit carried by a wave of adrenalin.
In the desolation of Antarctica, it felt like he was running on the moon. In Cape Town, he could see the rocky top of Table Mountain. When the group arrived in Perth on the third day, they ran in the middle of the night, under a starlit sky.
The pace was staggering. When each race finished, there was only time for a shower and a meal, and then people piled back into the plane and tried to sleep.
In Dubai, Gamblin finished the fourth race without incident. But when the group arrived in Madrid for marathon five, he felt something in his lower back: Spasms. It might have been the hours on the plane. Or the pace. Or the course — the fifth race on a slanted Formula 1 track. But when Gamblin embarked on marathon six in Fortaleza, Brazil, he knew for sure that something was wrong.
He was experiencing what some call the 'ultramarathoner's lean,' his back spasms so severe that he kept leaning further to the right. As he tried to grit through the race, his mind wandered. He thought of a colleague, Adam Berger, who had unexpectedly died last year. He thought of Melissa Smith, to whom he dedicated his trip. Finally, he realized: He had to give in.
Clark, he told himself. Your back's not cooperating. As much as you want to do this, and as much as your legs feel good, it's not going to happen.
He finished a half-marathon in Brazil, picked up a pair of walking sticks, and with his back still ailing, gutted through a final half-marathon in Miami. When it was finally over, he saw his family waiting at the finish line. Jan handed him his medal.
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It wasn't what he had dreamed of, and if the goal was seven marathons in seven days, he had technically come up short. But then he remembered a message he had received from one of his cancer patients.
The privileged get to choose their suffering.
He had wanted to raise money for testicular cancer research, and he had wanted to push people to aim higher, but as he struggled through the final two half-marathons — a suffering he had chosen — he realized the experience had done what he had hoped. It changed him.
He's become more deliberate in his daily life, more comfortable with failure and more intentional about surrounding himself with what he calls a 'culture of positivity.'
In the days after his final race, he thought back to his own battle with cancer. It was then that he had learned to practice what he preached. And now he felt the same sense of peace: The only way to know what you're capable of is to push to the ultimate limit.
'Don't be afraid to come short,' he said. 'It'll be much better than if you never set the goal at all.'
(All photos courtesy of Jan Gamblin)
