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Gordon Ramsay In 2013 , the celebrity chef took his skills to the Ironman World Championship and finished at a respectable 14:04:48. Since then, he's been an active participant in Ironman competitions around the world and has taken part in countless marathons and triathlons. Jack Taylor - Getty Images

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Sean Astin The Lord of the Rings star competed in the Ironman World Championship in 2015. He crossed the finish line at 15:30:31 and raised more than $25,000 for his charity #Run3rd , which provides support for running programs for underserved children, according to PEOPLE . Bryan Steffy - Getty Images

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Max Greenfield The New Girl actor has competed in multiple Nautica Malibu Triathlons, his first being in 2012. "It is an incredible event and it raises money for Children's Hospital Los Angeles for pediatric cancer research," Max told PEOPLE ahead of his fourth year participating in 2016. "Every dollar is necessary and goes to good use. As a parent, I can't think of anything more important." Christopher Polk - Getty Images

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Jennifer Lopez J-Lo is another star who's participated in the Nautica Malibu Triathlon. She competed in the 2008 iteration, finishing the 1/2-mile swim, 18-mile bike ride, and 4-mile run in 2:23:28and it was her first triathlon . Jean Baptiste Lacroix - Getty Images

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Matthew McConaughey There's no doubt that Matthew McConaughey is fit, but did you know he finished the 4-mile run portion of the Nautica Malibu Triathlon in 27:25? That's just slightly under a 7 minute mile pace. His final time was 1:43:48. Alright, alright, alright. Gregg DeGuire - Getty Images

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America Ferrera America Ferrera had a transformative experience running her first triathlon. The actress penned an op-ed about how she competed to silence the voice in her head that said she couldn't do it in The New York Times, explaining her fears and how she felt after. Oh yeah and then she completed a second triathlon ...and a third. @americaferrera - Instagram

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Jeff Conine Jeff Conine became the first Major League baseball player to finish the Ironman World Championship in 2008. The former pro athlete earned a time of 14:43:45. Steve Mitchell - Getty Images

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Tony Kanaan Racecar driver Tony Kanaan has been signing up for triathlons for decades. "I started swimming when I was a little kid racing go-carts because you can't really lift weights, so I started to swim to get stronger in my upper body," Tony told Active . "And I've always biked and the run just sort of happened. I thought, 'If I'm doing all three, then I might as well motivate myself to train more,' so I signed up for my first triathlon 18 years ago and I caught the bug." Slaven Vlasic - Getty Images

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Hines Ward The former Pittsburgh Steeler competed in the Ironman World Championship in 2013. He finished the 2.4-mile swim, 112-mile bike ride, and full marathon with a time of 13:08:15 . Jerod Harris - Getty Images

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Mel C Mel C lives up to her nickname Sporty Spice. The singer has been competing in triathlons around the world since 2011 . Ben Pruchnie - Getty Images

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Eric Byrnes The former MLB outfielder is a triathlon veteran, having competed in 11 full Ironman Triathlons. After his 11-year baseball career ended, he chose to pursue endurance sports. "The beautiful thing about triathlon is that it has no age limit, and the sport has nothing to do with how far or fast you go," Byrnes wrote on the Team USA site . "The only thing that really matters is that you go." Donald Miralle - Getty Images

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Ellie Kemper And now we've hit The Office portion of this list. Many of the cast members have gotten together over the years to participate and relay in the Nautica Malibu Triathlon. Ellie Kemper is one of them, who lent her legs to the running portion of the event . Todd Williamson - Getty Images

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Rainn Wilson Rainn Wilson, who famously portrayed Dwight Schrute in The Office, also competed alongside his costars. Too bad Jim wasn't there to pull a prank on him. David Livingston - Getty Images

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Ed Helms Ed Helms (a.k.a. Andy from The Office) also competed with his costars during their relay version of the Nautica Malibu Triathlon. Todd Williamson - Getty Images

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David Denman David Denman, who you might recognize as Pam's fianc Roy, has competed in several triathlons. He says he enjoys the three different disciplines when training. Noel Vasquez - Getty Images

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Jimmie Johnson NASCAR driver Jimmie Johnson has competed in about a dozen triathlons and 70.3s. He even finished one 72.3 when he made a wrong turn and added two miles to his race. Jerry Markland - Getty Images

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Natalie Morales Natalie Morales started running in 11th grade, so she wasn't worried about the running leg of her racebut the swim was a different story. "I was so afraid of the swim because I swam the course the day before the race and jellyfish were everywhere," she told Triathlete . "But in the end, the swim was the most exciting because I faced my fear and pulled it off." Vallery Jean - Getty Images

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Don Davey In 2012, the former NFL star completed the Ironman 70.3 Florida in 5:00:16 . Since then, he's traveled to Europe to compete and went to Hawaii for the Ironman World Championships. Sarah Stier - Getty Images

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Apolo Ohno Apolo Ohno used his Olympian contacts to train for his first triathlon. The former speed skater enlisted the help of swimmer Michael Phelps, the most decorated Olympian of all time. His first race was the Ironman 70.3 Boise, which he finished in 4:59:27. Dario Cantatore - Getty Images

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Jennie Finch Speaking of Olympians, pitcher Jennie Finch hung up her cleats in 2010 and traded them for running shoes in 2011. The softball player completed the Aquaphor New York City Triathlon in 2:51:15 in 2014, according to Triathlete . Icon Sports Wire - Getty Images

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Mario Lopez Mario Lopez loves to run, saying it's the best way to condition. The TV personality completed the Nautica Malibu Triathlon in 2009 in 2:03:17. Jean Baptiste Lacroix - Getty Images

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Claire Holt In 2012, Claire Holt took home the gold medal in the Nautica Malibu Triathlon. The actress clocked in at 1:44:00 minutes , which is seriously impressive. Christopher Polk - Getty Images

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William H. Macy What's the key to a successful relationship? Exercise. William H. Macy and wife Felicity Huffman compete in triathlons together, which is definitely #relationshipgoals. Jordan Strauss - Getty Images

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Felicity Huffman Felicity Huffman was likely the one to get Macy out and running. How do we know? She's completed in more than half a dozen triathlons and finished all of them in under one hour and 47 minutes. Jason Merritt/TERM - Getty Images

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Chris Harrison Chris Harrison is famous for helping bachelors and bachelorettes find love on TV, but he's also very athletic. He golfs and participates in triathlons. In 2010, he finished the Nautica Malibu Triathlon with an impressive time of 2:03:45. Jordan Strauss - Getty Images

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Megyn Price Megyn Price told Naturally Savvy that she started doing triathlons because it's important for women to set goals that aren't just about how you look. It paid off, because the Rules of Engagement actress took home first place in the 2010 Nautica Malibu Triathlon with a time of 2:10:23. Chelsea Lauren - Getty Images

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Teri Hatcher The Desperate Housewives star added "finish triathlon" to her bucket list in 2009 . That same year, she crossed it off as she passed the finish line. Since then, she's continued participating in triathlons. Noel Vasquez - Getty Images

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David Hasselhoff Everyone knows the Baywatch star can run. But he can swim and bike too. The Hoff participated on Richard Branson's team for the 2010 Virgin London Triathlon. Ben Pruchnie - Getty Images

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Anna Kournikova The tennis star is no stranger to the triathlon circuit. She often joins fellow athletes for relay triathlons around the world. Jason Merritt/TERM - Getty Images

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Ryan Sutter Bachelorette alum Ryan Sutter is very into triathlons. He's competed in numerous events, including the 2011 Nautica Malibu Triathlon, which he finished in 1:33:04. Tiffany Rose - Getty Images

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Jon Cryer The Two and a Half Men star finished the 2008 Nautica Malibu Triathlon in 1:53:36. The actor scared many when he crashed his bike four years later during the same race. Gregg DeGuire - Getty Images

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Alexander Ludwig Alexander Ludwig crossed the finish line with his brother Nicholas Ludwig in the 2018 Nautica Malibu Triathlon. It was the Vikings star's first triathlon, but Ludwig's already looking forward to this year's race, according to his Instagram . Ernesto S. Ruscio - Getty Images

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Alfred Enoch Alfred Enoch teamed up with How To Get Away With Murder costars Karla Souza and Jack Falahee for the 2016 Nautica Malibu Triathlon. Instead of training for their individual legs of the competition, they all trained together. Noel Vasquez - Getty Images

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James Marsden James Marsden takes part in the Nautica Malibu Triathlon every year to help him maintain his body. "It forces you to stay in shape because you never know when you're going to be asked to get naked," he told The Hollywood Reporter . In 2017, the triathlon fell on an important day: the day of the Emmy Awards. Marsden chose the race. Noel Vasquez - Getty Images

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Joel McHale Joel McHale's claim to triathlon fame is that he beat James Marsden in the running portion of the Nautica Malibu Triathlon in 2018. He likes to recruit new talent, too. While on The Tonight Show Starring Jimmy Fallon , McHale tried to get the host to commit to the event for 2019. Noel Vasquez - Getty Images

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Jennifer Garner Jennifer has participated in the Nautica Malibu Triathlon several times. More recently, the actress suited up for the Springs Back Triathlon, finishing with a time of 1:36:16 . Kevin Winter - Getty Images

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Scott Patterson When browsing through the Nautica Malibu Triathlon's celebrity division page , you might be surprised to come across Gilmore Girls star Scott Patterson. But the actor has always been an athlete, and even spent seven years playing minor league baseball. Jenny Anderson - Getty Images

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Zac Efron Zac swam, biked, and ran in the 2017 Nautica Malibu Triathlon alongside a very special competitor: his brother, Dylan. Noel Vasquez - Getty Images

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Mike Richter Former New York Rangers goaltender Mike Richter competed in his first full Ironman in 2007, clocking in at 12:49:10. "Sports, in its best light, is about challenging yourself and improving yourself as a person," Richter told The New York Times . "It's not about looking for a medal at the end of an event; it's about a journey in which your physical and mental well-being improves through physical activity." Ilya S. Savenok - Getty Images

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Tyler Wright Tyler had a long career in hockey, playing in 613 games. But the former NHL star took his athleticism in a different direction when he competed in the Ironman Canada for a Cause . Ian Tomlinson - Getty Images

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Robin Roberts The Good Morning America host poses at the starting line of a triathlon in 2006. Roberts was competing in the 20th annual Nautica Malibu Triathlon. Jesse Grant - Getty Images

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Bryan Greenberg Actor Bryan Greenberg grabs his bike as he transitions from swimming to cycling during the Lifetime South Beach Triathlon in 2016. Aaron Davidson - Getty Images

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Ali Landry The former Miss USA is seen completing the running portion of her first triathlon in 2012. Christopher Polk - Getty Images

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Tate Donovan Tate Donovan holds his sneakers, and a much needed water, in his hand after completing the 19th annual Nautica Malibu Triathlon in 2005. Gregg DeGuire - Getty Images

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Alison Sweeney Alison Sweeney proved her chops by winning 2nd place in the female individual category at a triathlon in California. We're sure her Biggest Loser costars are impressed! Christopher Polk - Getty Images

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Jason Collins Former NBA star Jason Collins hit the pavement as he competed in the Lifetime South Beach Triathlon in 2016. Johnny Louis - Getty Images

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David Duchovny David Duchovny exits the ocean after completing the Nautica Malibu Triathlon's swimming portion of the race. The actor has been a longtime supporter of the event, which raises money for the Elizabeth Glaser Pediatric Aids Foundation. Frederick M. Brown - Getty Images

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Mark-Paul Gosselaar Saved By the Bell's Mark-Paul Gosselaar warms up on his bicycle before the start of the Nautica Malibu Triathlon in 2005. Gregg DeGuire - Getty Images

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Amanda Beard Amanda Beard may have had an advantage in the swimming portion of the race. The swimmer and seven-time U.S. Olympic gold medalist looked pleased with her results after competing in a charity triathlon in 2005. Ana Elisa Fuentes - Getty Images

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Scott Eastwood Scott Eastwood fave the cameras a smile as he prepared for the start of the race. The actor participated in the Lifetime South Beach Triathlon in 2016. Aaron Davidson - Getty Images

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Monique Coleman The High School Musical star was cheered on by fans as she completed the final stage of the Nautica Malibu Triathlon in 2008. Jason Merritt/TERM - Getty Images

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Tiffani Thiessen Tiffani Thiessen from Saved By the Bell was all smiles as she prepared to compete in the Nautica Malibu Triathlon in 2011. Tiffany Rose - Getty Images

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Will Ferrell Will Ferrell looked as if he was on the set of one of his comedies wearing a tank top, short-shorts, and sweatband to compete in a triathlon in 2002. Steve Grayson - Getty Images

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Jenson Button Formula 1 driver Jenson Button traded in his car to compete in a different kind of race in 2013. Button competed in the Vodafone Mclaren Mercedes Ironman competition in Berlin. Boris Streubel - Getty Images

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Jeremy Piven Jeremy Piven flashes a smile as he accepts his medals for his performance in the 23rd annual Nautica Malibu Triathlon in 2009. Valerie Macon - Getty Images