There are two kinds of people in the world: People who take one spinning class and quit, and insane people who not only keep at it, they even buy the special spinning shoes.

Spinning, in case you aren't familiar, is cycling; an intense cycling class set to music, lasting 45 minutes to an hour. Or, as our instructor Mario described it last week, only "nine songs." Always worry when the length of a fitness class is described in terms of songs instead of minutes. Right around song No. 6 --and you will be counting-- you'll know what I mean. It's all part of the deception.

I tried spinning because I heard it was an excellent way to improve cardiovascular health and burn fat. That's the good part. They always tell you the good part.

People who have done it tell you the rest.

"Ever taken spinning?" I asked a friend at the gym some months ago, while looking over the schedule of different classes.

She rolled her eyes. "It's hard," she said. "Really hard."

It is upon hearing this information that every person views himself or herself in the best possible light. When someone tells us a class is "really hard," we always think that's only for everyone else.

It won't be hard for me. I can do it. I mean, it's just riding a bike. A stationary bike. I'm Lance Armstrong.

Torture awaits, and the secret is in the bike. The pedals drive a big heavy, metal wheel, which can be set at varying resistance. At its easiest setting the wheel spins freely, so don't worry about remembering that one because you'll hardly ever use it. The other end of the spectrum is like riding a bike while immersed in wet cement, and you will learn this setting very well. The general rule is you can always add a little more resistance.

The class simulates flat road rides, hill climbs, even steeper hill climbs and, alas, downhills. There are three different hand positions on the bike. On hill climbs, for example, you stand up to pedal while bent at the waist with your hands all the way forward. This position was created to remind you that it wasn't so bad while you were pedaling in the saddle, you just thought it was.

Then there's my favorite -- the jumps. Jumps are where you stand up to pedal four or five strokes, then back down four or five strokes, back up, then down, up, down.

The instructor announces each change with pep rally glee, which is intended to be inspiring but, as your fatigue grows, becomes dreaded and then annoying. While climbing hills they say, "Almost to the top," which means you aren't. They announce, "A little more resistance!" as if they expect the class to break out in celebration.

But the instructors also tell all spinners, particularly the new ones, to go at their own pace. This is determined thusly: If you collapse during the class, you're going too hard. If you feel like you're about to collapse, welcome to spinning! Pace only matters during your second class, should you decide to come back. The first time you spin, you will realize about two-thirds of the way into the class that you have no pace.

Love of spinning develops through loss of hatred. You hate it after your first class; most people still hate it after their third or fourth class. The more you do it the less you hate it, and that's how you know you love it.

The gym I belong to has an excellent spinning room, with the bikes arranged on stadium-style platforms, a great sound system and low lighting. You're almost spinning in the dark, which I initially thought was to help the class concentrate.

Now I know the lights are kept low for a few reasons. One is so others can't see what you look like while spinning, because you don't look good. The other is so that as the weak succumb and fall off their bikes, little men can run in and drag them out of the room without alarming the rest of the class.

I won't be failing off the bike, which is not to say it isn't tempting. I just bought the shoes, which come with little clips that lock on to the pedals so that there is no escape. Just another hill to climb, from my usual spot in the back of the room, on the way to song No. 9.

Viva la resistance!