In the topsy-turvy world of trampolines, everything that goes down must come up again. Back in the 1960s, trampoline parks were, much like hula-hoop competitions, a big fad. But they were done in by personal-injury lawsuits and had long been forgotten by most people, including the two men largely responsible for their contemporary rebirth: the father-and-son team of Rick and Jeff Platt.

Here is the original pitch: Let's create a new "3-D" pro sport that involves a giant trampoline, two rotating hoops suspended 7 feet in the air and players who score by jumping through the hoops with the ball.

Jeff Platt is not just another success story; he’s a Washington University success story. Platt is the owner of a major franchise called Sky Zone, an idea created during his time as an undergraduate at the Olin Business School. Sky Zone, a recreational facility composed entirely of trampolines, has grown to incorporate five locations across the United States.

After striking gold in Chesterfield and Las Vegas, Rick Platt and his son, Jeff, plan to expand their SkyZone Trampoline Center LLC business nationwide with eight new facilities by the end of next year.

When Rick Platt started SkyZone three years ago, he couldn't get a bank to back the project. Platt approached lenders with a plan to link trampolines to form an enclosure the size of a small basketball court -- something that had not been done before. His idea was to develop a game using the SkyZone court and charge admission fees. "I thought it would be cool to own my own sport," he said.

Some just bounce up and down. Others do zigzags across the unstable surface, while others do drills designed to get their hearts racing. Finally, some, quite literally, jump through hoops.

No time for breakfast and too much TV time are among the factors that can raise the risk of diabetes, Fitness magazine re- ports. In an article in its April is- sue, the magazine outlines nine surprising risk factors for the dis- ease, which affects about 21 mil- lion people in the United States.

The University of Nevada, Las Vegas, is the quintessential commuter school, boasting 28,000 students — only about 2,000 of whom actually live on campus. This fact presents campus recreational services director Jeff Wells with the sometimes daunting task of persuading students to participate in intramural programs.

The nation's second all-trampoline SkyZone Recreational Center is scheduled to open in Chesterfield Commons in June.

Richard Platt, owner of SkyMania FunCenter, 4915 Steptoe St., does not like to let anyone leave his building without trying out his one-of-a-kind trampoline course.