There were women of all shapes and sizes (college coeds to grandmas), exercising on a circuit to disco-fied 70's cover songs. Every 30 seconds, a pleasant - if somewhat robotic voice - commanded them to "change stations now." Some were actually sweating, so I decided to give the machines a try.
Curves, I take it all back. Your hydraulic resistance machines provide a helluva workout. It all depends on how fast you pump them. My glutes are actually sore this morning after 30 minutes, or 3 trips around the circuit last night. AND, I didn't tweak my ankle again...bonus!
So, yeah, I signed up. I may be hearing "change stations now" in my sleep, but that's a chance I'll have to take. Here's to curves with smaller radii!