AP Photo/Tina Fineberg We loved Sweatin' to the Oldies with Richard Simmons.

Jacki Sorensen's aerobic dancing. Judi Sheppard Missett's Jazzercise. Jane Fonda's complete workout.

For almost four decades, we've been doing group fitness classes -- skipping, heel hopping, grapevining and running in place -- hitting the fitness center for classes using steps, slides, mini trampolines, treadmills, cycles, tubes, dumbbells and giant bouncing balls.

We've danced on poles like we were strippers, salsa-ed to Latin music, stretched on a Ladder Barrel, and sat in overheated rooms with our legs crossed imagining we were flowers.

And it's only gotten more unsual with time.

There's Super Hero Training. Cardio striptease and Zumba -- billed as a "feel-happy," Latin-inspired workout. And yoga and pilates? They're together at last.

Perhaps one of these days fitness centers will run out of new ideas. Then we'll cancel our memberships and get back to power walking. But for now, fitness centers keep coming up with some interesting classes.

Check out some of them in this asap video report.

Megan Scott is an asap reporter based in New York.