The last time I was in a spin class, it was because I was already doing my own spinning and didn't know one was going to start.

I had done about 45 minutes of moderate-to-difficult noodling around when people started showing up, getting their spin bikes ready and warming up. I asked the woman next to me if it was a class, which she confirmed.

I ended up spinning twice as long as I had planned, which was a total of either one or two hours -- I forget now (I do remember that it turned out to be about as long as my typical rides, so I'd guess two hours). I had generated a couple puddles of sweat on the floor, while the woman next to me and her friend were barely glistening -- so I figured that, like any other exercise, you get out of it what you put into it.

I'd really like to see what resistance settings other spinners use, but I suppose that's one of the secrets of spinning. It's not like pushing weights, where everyone can see what you're lifting -- if you work out enough, you don't care what anyone sees you doing, but self-conscious types can get embarrassed. On a spin bike, though, if you're keeping your resistance low, it's just between you and your bike.

Speaking of resistance, I'd like to see a setup that changes resistance as quickly and consistently as changing gear on a regular bike. Changing gears on a trainer works really well, but I use it less than I planned because my downstairs neighbor wonders what's going on (maybe I should take it to the roof deck ).