NEW YORK - Some 36-year-olds hit the golf course to unwind; Pearl Lin prefers fine-tuning his back flip.
Less than a year ago, Lin, a New York City boutique owner who had no childhood gymnastics training, could barely master a forward roll. Now, he's defying gravity and his biological clock.
Whether reviving a childhood passion or following the leads of their own children, more adults are stepping off the sidelines onto gym mats, playing fields and ice rinks. Small-town instructors and national sports organizations report a spike in adult participation in sports generally dominated by kids.
"I used to go to the gym but it turned into a chore," said Daniel Lewis, a 26-year-old New York University law student who attended a recent gymnastics class with Lin at the Chelsea Piers recreation complex on Manhattan's Hudson River shore. "With gymnastics, you're getting great exercise and also learning real skills."
Chelsea Piers' 25,000-square-foot gymnastics facility advertises the largest adult gymnastics program in the country, attracting both first-timers and professionals. Classes are split nearly evenly between men and women, instructors said. Participants hail the sport's almost meditative effects, but the regulars' sharply defined muscles point up other benefits.
Other activities focus more on fun than physical discipline. The Seattle-based group Underdog Sports offers adult leagues for elementary-school staples - dodgeball, kickball and flag football.
Its kickball league, with members ranging in age from their 20s to 60s, had 150 participating teams in Washington last year, said its director, Lawrence Martin.
Underdog prides itself on a laid-back environment where players can "let go of the stress they find in their everyday lives," said Martin, who enjoys seeing the role reversal of kids sitting in the stands watching their parents play.
The Sports Clubs Network -which has 135 U.S. health centers - offers hip-hop dance, a ballet workout and "urban rebounding," exercises on miniature trampolines.
"Within the past five years, we've started really seeing a lot of interest in childhood activities being incorporated into exercise classes," said Allyson Donnelly, the network's director of group exercise. "It's the variety of the activities, and the novelty, and there's definitely an element of escapism about them: You can go into a studio for an hour and be a salsa dancer."
The ballet class offered by the Sports Clubs Network, the NYC Ballet Workout, can be done at home, too. Since it was created in 1997, more than half a million copies of its videos and DVDs have been sold, along with 100,000 instructional books, said Deanna McBrearty, a representative from NYC Ballet.
And with the influence of the Winter Olympics and the Fox TV network show "Skating with Celebrities," figure skating is becoming particularly popular among adults.
"We've noticed a real increase," said Antonio Conte, chair of the U.S. Figure Skating Association's adult skating committee. He said he expects about a 10 percent jump in participation after the Olympics.
"As a kid, you do an activity because you love it, not because it burns calories," said Conte, who first put on a pair of skates 10 years ago when he turned 30. "Adults are looking for that, too. People are living to be older, and they're rekindling their interest in something they used to do or have always wanted to do."