Mike Kloser was a professional mountain-bike racer, and after his career was over he spent years traversing unmarked wilderness courses in adventure races.

Once he hit his 50s, Kloser, who lives in Colorado’s Rocky Mountains, saw no need to slow down much. On any given day, he can be found riding the trails around the Vail Valley, running up and down Aspen Mountain, competing in obstacle races or skiing the snow-capped mountains.

“I’m not the kind of guy that likes working out indoors,” the 53-year-old Kloser said. “I’d rather be out in a blizzard skiing or doing something outside than working with a trainer in a gym.”

Kloser already was inclined toward more adventurous activities. He is, after all, a former professional athlete and lives in an area where fitness is woven into the way of life. But he isn’t alone among his baby boomer peers.

An adventurous generation growing up, many boomers have barely slowed down in their 50s and 60s. The oldest of the baby boomers hit 70 this year.

Golf, tennis, water aerobics, treadmills? Those are all fine, but also can be a bit boring for a generation that likes to have fun.

So as previous generations tended to steer away from extreme sports, baby boomers seem to gravitate toward them. They can be found among the mostly younger crowds surfing, rock climbing, mountain biking, ocean kayaking, even skateboarding and skydiving.

According to a 2015 National Sporting Goods Association study, there were 698,000 people between ages 55 and 74 who participated in off-road mountain biking, 402,000 doing open-water scuba diving, 155,000 snowboarding and another 49,000 into skateboarding.

“We all have that in us, like why shouldn’t we be having fun doing what we love to do?” said Barbara Odanaka, a children’s book author who started a moms skateboarding group in Southern California. “We’re not just stuck to typical activities, typical behaviors as our parents’ generation was.”

Baby boomers come by this call to action honestly. They grew up in an era when fitness moved toward the forefront of American society. Surfing, jogging and weightlifting all became popular as boomers came of age. People began paying more attention to their health.

According to AARP, less than 24 percent of American adults exercised regularly in 1968. That number was up to 59 percent by 1984. Life expectancy also rose from 69.7 to 75.4 years in a span of 30 years ending in 1990.

Living longer than their parents, baby boomers also stayed active longer.

“I think the mentality of our age group has changed,” said Kloser, director of activities at Beaver Creek Resort. “We’ve been active 20 or 30 years of our lives, and we just aren’t ready to become a seven-day-a-week couch potato. We want to keep active.”

Odanaka, 54, has done it on a skateboard — with other baby boomers from around the country. She skated as a kid, even earned a spot on Hobie Skateboards’ amateur team, but gave up to focus on competitive running. She was steered back to skateboarding a quarter century later by a therapist who told her to find something she used to enjoy as a way to take a break from a colicky baby.

Odanaka immediately rekindled the connection with her board and started riding every day, often joining the neighborhood kids who would knock on the door to see if she could come out to skate.

While promoting her first book, “Skateboard Mom,” in 2004, she hosted an event at a skate park and invited other skateboarding moms. That event launched the International Society of Skateboarding Moms, which evolved into the nonprofit Skateboard Moms & Sisters of Shred.

The organization now has roughly 400 members, ages 20 to 70, across the United States. Odanaka also has a group she skates with locally, often turning heads as they roll up and down the slopes of the skate park.

“The teenagers usually look at us like, ‘Oh my God, what is this?'” said Odanaka, a former reporter for The Los Angeles Times. “And I can’t tell you how many times the little kids have asked me for money for the soda machine or to tie their shoe. But by the end of it, there’s usually one kid who says: ‘I wish my mommy skated like you.'”