Fastening the boots, not for roller blading. These are kangoo jumps.

"It definitely challenges your balance, but it's very bouncy like a trampoline or something," says Diana.

"it's exactly like a trampoline, only on your trampoline you can only be in your backyard. On my trampoline, I can go to the beach," says Jill Boyer-Holland, US Coordinator for Training and Education.

Or to an indoor kangoo class at hospital fitness center.

"This is the world's lowest impact shoe, and it reduces the impact up to 80% of any and all athletic activity. So what that translates into, your knees are gonna last longer, your hips are gonna last longer," says Boyer-Holland.

It's called rebounding. Instructor Sandra Bassett says it takes a little getting used to. This is only Marie Schultz's second class. And she's definitely caught on.

"It's less impact but more intense than anything I've done," says Marie Schultz, class participant.

"Because the boots weigh two pounds and the larger the boot...two pounds each, you are weight training. As you jog you are lifting weights," says Bassett.

Because of the bouncing it's not recommended during pregnancy, but these women say they feel the benefits.

"I actually came because I was jogging on hard pavement and getting back problems and it's alleviated my back problems. It's great for the spine," says another participant.

"You're getting your heart rate up, but there is no joint pain," says a participant.

57-year-old Jan Reyna says she's tried many different forms of exercise over the years and kangoo has given her noticeable results.

"Everything a woman wants...long, lean, toned muscles," says Reyna.

Prices for the boots start at 219 dollars, but in the class you can rent them, to try out how it feels to put some major spring in your step.