This article originally appeared on Trail Runner

Some athletes make epic feats look easy, and some athletes make them look fun. Heather Jackson, 39, does both. Jackson can clearly go to the pain cave, but she always looks like she's a kid at recess, full grin. Maybe that's because she lets herself explore -- try new things, be a beginner, and put adventure above all.

Before dominating some of the biggest races in the world as a professional triathlete for nearly 15 years, Jackson was a pretty serious hockey player. After a Division 1 collegiate career, she played for the U.S. Women's National Team.

Then, after winning six Ironman races, 16 half-Ironman races, and placing fifth or better at four Ironman World Championships in Kona, Hawaii, Jackson transitioned again last year. This time to ultra trail running and off-road cycling.

Triathlon to Trail Running

"This year has been amazing so far for me," Jackson said of her first year post-triathlon. "Just so fun, so refreshing, lighter than the last 10 years or so. Everything I've tried has been so new and fun." And she's tried a lot. She came in 5th at the Javelina Jundred last year. She won the 50K race at the Canyons Endurance Runs by UTMB in April. She took a DNF at Western States 100, but is ready to take on the 55K UTMB OCC on August 31. It's all about learning, which she's the first to admit is never linear.

Meanwhile, by the way, she's also been racing bikes quite a bit. Jackson is part of the LifeTime Grand Prix, which includes 7 off-road events all around the U.S. over 7 months. She's finding that she enjoys the balance of learning how to be competitive in trail racing and off-road bike racing. It wasn't necessarily that Jackson was sick of triathlon, it was that she wanted to try other things.

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"I remember watching the live coverage of UTMB last year and just being like, 'That is insane, people running up and down the mountains.' It was inconceivable." But also, she wanted to do it. She wanted to try the things that she had always watched from afar.

"For me it's all about keeping it fun. [Competing in bike and running races] keeps it fresh. I’m always looking forward to the other one, even in training. If I focus on my long run one day, then the next day I get to ride, so it never gets stale."

As for the conditioning, Jackson tends to think the biking helps the running more than the other way around. "When I'm on the bike I’m building endurance and getting that cardio work without the pounding on my legs." Though she admittedly knows that she needs to practice more of the technical mountain running in order to hone those skills.

Heading to France

Even though Jackson dealt with some ankle and hamstring issues after Western States, she couldn't turn down the offer to join the Hoka team in France. She'll race the UTMB OCC 55K, and is excited to debut in true high-mountain racing. "Why wouldn’t I try it for the experience? I’m not going in with any sort of expectations at all. I’ve used polls like three times in my life, so I just want to see what it’s like, and see the event, and enjoy every second." Jackson said she's going in relaxed and hoping to take it all in as an introduction to more technical trail running. "I'm looking forward to the whole week in France."

The UTMB OCC 55K might not be the crown event, but it climbs 11,235 feet. So, plenty intense for a first-time UTMB experience. The course crosses the Franco-Swiss border via the Balme pass with views of the Mont-Blanc massif. Once runners have reached the last climb to La Flegere, they descend to the iconic finish line in the center of Chamonix. While Jackson thoroughly enjoyed the triathlon scene and the community she had there, she feels like the trail running world suits her better. "I don't know if I would say that 15 years ago, but it feels right for me now." Triathlon training is very regimented, while trail running feels more flexible to Jackson -- more about going on adventures. "In the trail running world, if I'm training in Colorado, people are like, 'Oh, let's go for a run!' And it's more about going on an adventure instead of going out and hitting one-mile repeats over and over."

She also enjoys that there's more unknowns about trail racing. In an Ironman race, everything was very calculated. And all of the athletes know each other so well that they could predict exactly what someone's swim time would be, exactly what their bike splits would be, and down to the minute, how fast they would run the marathon. "With trail running, every course is different, the conditions are different, it can be hilly or rocky. Every single thing is so different every time. For me that's just so cool."

After UTMB, Jackson is looking forward to her remaining bike races, and then will head back to the Javelina Jundred in October in hopes of a Golden Ticket.

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