The ultramarathon legend who ran 350 miles nonstop says the key to doing hard things is simpler than most people think

For decades, scientists have tried to understand what separates people capable of extraordinary endurance from everyone else. Is it genetics? VO₂ max? Pain tolerance? Mental toughness?Dean Karnazes has spent more than 30 years giving them a remarkable case study.He's run 50 marathons in 50 states in 50 consecutive days, crossed Death Valley in the middle of summer, and in 2005 set the record for the longest nonstop run — covering 350 miles in 80 hours and 44 minutes.Even that wasn't enough."I actually made it 350 miles, which was somewhat of a letdown because I thought maybe I could run 500 miles," Karnazes told me. "That was kind of the ultimate goal." His world record still stands today, 21 years later.After decades of ultrarunning, Karnazes says he's learned that doing hard things comes down to a handful of simple habits that anyone can practice.Don't make winning the goal Courtesy of Dean Karnazes Karnazes has finished on the podium plenty of times, but he says that's never been what pulled him to the starting line."I do it for the adventure," he said. "Both the inner and the outer adventure. I've never really said I want to win a race. I just thought, be the best Dean that Dean can be on race day." He says approaching races that way has changed how he defines success. The podium, if it comes, is just the cherry on top. That mindset, he says, has kept him motivated through hundreds of marathons and ultramarathons, long after chasing trophies stopped being interesting.Redefine what success looks like Karnazes ran 350 miles nonstop, setting the world record for the longest continuous run by any human. Courtesy of Dean Karnazes When Karnazes gives advice to new ultrarunners, he doesn't start with mileage or pace."Just set your goal on finishing," he said. "Don't say I want to do it in sub five hours or sub six hours. Just say, 'For me, success is reaching the finish line before the cutoff.'" Karnazes says that approach has a way of changing how you see your own limits."You'll prove to yourself that you're better than you think you are. And you can go further than you think you could." Keep moving, even if you have to slow down Karnazes has placed in many races, but he says that's not what drives him. Courtesy of Dean Karnazes The advice sounds simple, but following it is another story.At some point during his 350-mile run, Karnazes stopped trusting what he was seeing.After nearly three days without sleep, he said he started hallucinating. He felt as though he had left his own body and was watching himself from above."When you're in these altered states, it's as though you don't have conscious control of your mind," he said. "You're fighting your mind to stay present, but your mind gets away from you." Despite that, he kept running.I asked Karnazes for his advice to aspiring ultrarunners who worry they'll hit a point where the pain becomes too much."You walk if you have to," he said. "You slow down, you push through the pain, and you come out the other side, and you're rejuvenated." Read next Business Insider tells the innovative stories you want to know Business Insider tells the innovative stories you want to know Business Insider tells the innovative stories you want to know Business Insider tells the innovative stories you want to know Jessica Orwig is a senior editor at Business Insider, where she collaborates with reporters, editors, and producers across teams to shape, write, edit, and publish stories that connect with a global audience. While her roots are in science and technology journalism, her work today spans business, careers, culture, and the big ideas shaping the future.She earned her Master’s in Science & Technology Journalism from Texas A&M University and holds a Bachelor’s in Astronomy & Physics from The Ohio State University. Throughout her career, she’s helped lead coverage on everything from space exploration and climate change to innovation, the future of work, and evolving cultural trends.Career HighlightsLed coverage on scientific milestones, including:Blue Origin's inaugural New Glenn launchIntuitive Machine's groundbreaking moon landing for the USSpaceX’s Polaris Dawn historic spaceflight NASA’s Parker Solar Probe Historic FlybyJapan’s SLIM lunar landingThe first image of a black holeIndia’s historic Moon landingSpaceX’s inaugural Starship-Super Heavy launchDiscovery of gravitational wavesNASA’s Pluto flybyReported on breaking news and scientific discoveries, including:Microplastics in the human brainPeregrine Mission One’s failed flightThe Palisades firesSpaceX Starship explosionsDark Energy Spectroscopic Instrument’s 3D map of the universe and what it revealsA local cosmic void that shouldn’t existThe Boeing Starliner missionMexico City’s water crisisEarth’s mysterious inner core behaviorPopular stories she’s edited on science and health:What it will take to modernize the American grid and usher in the clean-energy revolutionI study toxic microplastics. 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