If you've ever jumped on a big outdoor trampoline, you have an inkling of the allure of Sky Zone. To get the full effect, multiply the bounce factor times dozens of trampolines, move it all inside, put trampolines on the walls and add dodge ball, basketball hoops and a foam pit.

Since the first Sky Zone opened in Las Vegas in 2004, indoor trampoline courts have popped up across the country. They arrived in Minnesota a year ago, when the first Sky Zone franchise opened in Plymouth, followed by a second in Oakdale this fall. A similar company called Air Maxx opened in late summer in St. Cloud, and Zero Gravity just opened in Mounds View.

I tried the Oakdale Sky Zone recently with a friend and five kids. Unlike the inflatable playgrounds like Pump It Up, indoor trampoline courts delight teenagers as much as toddlers. Sky Zone in Oakdale hosts jump nights for teens and exercise classes for adults, and next year it plans to add dodge ball leagues.

Tickets are sold for specific time slots, and buying tickets online is smart if you come on a weekend. Twenty-four birthday parties were scheduled for one recent Saturday, leaving few spaces for drop-ins. We were lucky and happened to hit a slow day with 50 jumpers signed up for our session. The maximum is 125 jumpers, and I can't imagine navigating that crowd.

To save time, we filled out waivers online at home. After we checked in, we put on the required soft blue boots and then watched the digital clock. At 1:59:59, a voice broke into the music and announced the start of the 2 p.m. session. Kids ran up the steps and dove onto the trampolines.

The space is divided into five zones enclosed in black safety netting. My 12-year-old son and two friends headed for a dodge ball court. I followed my 5-year-old daughter, my friend and her 9-year-old daughter to the free-style court, where 50 trampolines butt against each other like squares in a checkerboard. Thick pads cover the seams, and trampolines line several walls. Attendants remind you of the rules - one person per trampoline, no back flips, double flips or flips from one trampoline to another. Easy to follow, since my family can barely do somersaults.

The first jumps were thrilling. Boing...boing...boing ... I discovered that if you wave your arms in big circles you go higher. Watch out, Winter Carnival! Here comes the next bouncing girl!

I spotted a young girl leaping from one square to another in single bounds like a kangaroo. A teenage boy in jeans and a white tank top gave new meaning to the phrase "bouncing off the walls." Two sisters did front flips while their parents filmed them from the sidelines. I played follow the leader with my daughter. In 15 minutes, we were

Alexis Ault, 16, of Mounds View leaps into the "Foam Zone" at Sky Zone. (Pioneer Press: John Autey)
exhausted.

"I call it stealth fitness, because you don't really know you're getting a workout," said Oakdale general manager Greg Hansen.

"A lot of activities today are very sedentary - you sit in front of screen," he added. "Everyone leaves here a sweaty mess and all smiles. It really gets your blood pumping."

LEAP OF FAITH

Sky Zone evolved out of a failed effort to create a new professional team sport played on trampolines. A father-and-son entrepreneur team, Rick and Jeff Platt, opened a court in Las Vegas. It never took off, but the neighborhood kids begged to jump on the trampolines, so the Platts decided to charge admission. The first franchise opened in Sacramento in 2008. A dozen have opened across the country with another dozen set to open by early 2012.

After a break to catch our breath, our group headed to the foam pit where an attendant reminded us to empty our pockets. He said has found iPhones at the bottom of the pit.

The two girls skipped down the trampoline, flung themselves into the air and landed in the pile of foam cubes. I jumped tentatively; wondering if diving into anything, even foam, was a good idea after age 40. But it was a squishy landing. Climbing out of the pit was what I should have worried about. You can't make a graceful exit wading through foam blocks.

Dodgeball was the favorite activity for the 12-year-olds.

"You could bounce to catch the ball and bounce to dodge it," said my son. "It's like ultra dodge ball."

The Sky Zone lounge area includes lockers, changing benches, a concession stand and tables. (Pioneer Press: John Autey)

They played a pick-up game with young teen boys who were there for a birthday party. The attendant suggested the fourth-grade girl in our group play in a less competitive game in another court, but she opted to play with the bigger kids. Even we two moms joined the game for a while.

FUN FOR ALL

We weren't the only parents jumping with our children.

"I think the adults had more fun than the kids," laughed Andrew Hegstad of Stillwater. He and his wife jumped for a half-hour with their two children, Severin, 9 and Marit, 7. Now, both children want to celebrate their birthdays here.

"We decided to come because it was such good exercise," said mom Becky Hegstad.

Nearby, 10-year-old Peyton Grufman was sipping ice water, her freckled face pink with heat and exertion.

"It's a lot of fun," the Woodbury girl gushed. "But you get sooo tired."

Grufman and her friend Kaitlyn Wyman did flips into the foam pit while mom Alisha Weber sat at a table and did her flipping through cookbooks. At $24 for two kids, it's was an expensive outing, Weber said, but worth it.

"This is my time to relax and read," said Weber. "I get to enjoy myself for an hour without getting bugged by anyone. I know they're safe, and someone else is watching them."

Maja Beckstrom can be reached at 651-228-5295.

THE SCOOP

What: Sky Zone Indoor Trampoline Park

Where: 595 Hale St., Oakdale

Information: 651-200-3383 or skyzonesports.com

Hours: 3 to 8 p.m. Tuesday through Thursday, noon to 9 p.m. Friday, 10 a.m. to 10 p.m. Saturday, 11 a.m. to 7 p.m. Sunday

Cost: $8 for 30 minutes, $12 for 1 hour, $16 for 90 minutes, $20 for two hours; deals for late-night sessions geared to tweens and teens

Target audience: Best for ages 5 and older

Crowd pleaser: Defying gravity

Avoid: Getting overheated. Wear short sleeves, even shorts.

Tip: Buy tickets and fill out electronic waivers online from home. Leave valuables in the car or bring quarters for a locker.

More: Read previously published Family Outings at MinnMoms.com/outings.