TRAMPOLINES make me want to pee. It's not like puddles of urine appear at my feet, but all that jumping... it gives a girl urges. So huge success story when I went to Sky High Sports, Tigard's ginormous indoor trampoline park: I kept my pee in, guys! And I bounced a lot! And according to science (MAYBE FROM THE ROYAL INSTITUTE OF UNSTABLE SURFACES!), I burned over 1,000 calories during that hour.

When some cohorts and I arrived at the bland industrial building, our very perky instructor directed us to find a jumping spot in one of the facility's trampoline rooms, a huge space divided into individual trampolines, with additional tramps lining the walls. There was room for two-dozen AIRobicizers. The premise of the class is simple: Make the floor jiggly while doing garden-variety aerobics and it's bound to be a tougher workout. Tough it was. We did a bazillion burpees, squats, sit-ups, butt-drop bounces, and jumping jacks—all while challenging our bladders to remain pure of heart. It was exhausting, and the next day my core was the sorest spot, which is exactly where I wanted to feel the drubbing.

As a bonus, when the official class was over, instructor Suzy Jumpsalot opened up one of the facility's other features: the foam pit. Much like a Chuck E. Cheese ball pit, it's filled with squishy blocks and sometimes, screaming toddlers. There I met more sweet success... I only hurt my neck a little when I jumped in! But it was in the pit that I probably got the best gut workout, laughing over our ridiculous upside-down flailings. It was a fun workout all around—silly and difficult and full of sweat, which is gross to see bumping up and down on trampolines, but a definite confirmation of effectiveness.

AIRobics, Sky High Sports, 11131 SW Greenburg, Tigard, Tues & Thurs 6 & 7 pm, Sat 9:30 am, $7 drop-in,