Exercise adds years to our lives. That's why, despite my secret love of slothfulness, I am serious about physical fitness. This means running over to the gym every day and throwing my body around for a few hours just so I can be the picture of health with the added perk of having buns of steel.

It's not that I mind showing off a well-toned bod, but let's face it, most of my daily stops are the supermarket, the hardware store and dry cleaners. Does anyone at Stop & Shop really care what I look like when I'm pushing a cart down the frozen food aisle? Is having a tight tush going to increase my ability to buy groceries?

What I have noticed since I've embarked on an exercise regime is 1) it hurts; 2) I'm getting too old for this sort of physical abuse. So, when I found myself in a contortionist's position, I asked the big question no woman should ever pose to her exercise instructor: "What's the point of all this, anyway?"

"The point," Buck said, placing my head in between my knees, "is that you will be a heart-healthy person who can face life knowing you are living up to your personal best."

People named Buck were put on this earth to make such statements, and though it may come as a surprise, Buck isn't even a guy. She's a woman with big, bulging biceps and buttocks so firm you could shoot bullets at them and they would ricochet right off without Buck ever feeling a thing.

I am just delusional enough to think if I continue on the road of death-by-exercise, I, too can have a rear end like Buck's, which is more attractive then a well-conditioned heart any day. Nobody ever gets to see my heart while almost everyone gets to see my booty. Thus, I joined Buck's class five days a week figuring I'd have five times a greater chance of developing a Buck-type body.

This had one drawback, however. It meant I must also purchase the food that Buck eats. This, she explained the first day, was a required part of the program.

"This is your breakfast," she said, handing over two brown objects that resembled something my next-door neighbor's dog, Jake, deposits on my lawn every morning.

"And this is your lunch," Buck said, distributing two dog-biscuit-size crackers. These, I believe, were actual dog biscuits. For dinner, she placed a sealed baggie in my hands consisting of a four-course meal in one easy-to-swallow pill. "All of these meals add up to a well-balanced, nutritionally-sound package," she reported.

"I suppose that means Twinkies are out," I said.

But who was I to complain? Obviously, Buck knew her stuff. How else could she have achieved a figure to die for, which, if I attempted to emulate, would probably kill me? And so, I dragged my tired body over to Buck's place and desperately tried whipping it into shape. The good news: I pulled two muscles, including a hamstring ,and dislocated my neck from continually forcing my head between my knees. I now had a reason to quit.

"A few aches and pains shouldn't stop you," Buck said. "It goes along with the territory. Just work through the pain."

I failed to mention that besides being an exercise instructor, Buck is also a sadist.

Then a miracle occurred. By the end of the third class, I felt no pain at all. Instead, I was completely numb from my head down to my toes. All the blood had drained from my vital organs as I prostrated myself on the floor. One more leg lift and I would be pronounced legally dead. This, according to Buck, was not a viable excuse for cutting class.

"Next session, we're going to do pulses," Buck announced.

I had never actually taken a pulse. Once, years ago in home economics, I took what I thought was the pulse of my classmate, Deanna Whitcomb, who passed out because I had pinched her radial artery too hard. But taking my own pulse and changing a flat tire were two challenges I had never successfully met. I relied on Triple A for all of my flat tires. I asked Buck if instead of taking my pulse, could I call the guys and have them do it for me?

"There's nothing to it," she said. "All you have to do is count heartbeats."

But after what she had put us through, I wasn't sure if I even had a heartbeat.

During our next session, luck was with me. I couldn't find my pulse. How could a person without a pulse be required to participate in class? By all rights, a person without a pulse should be able to lie down and take a nap. "Watch me," Buck instructed, landing directly on her pulse point. "See how easy it is? I want you to try again. We need to measure our pulse rates in order to design individual exercise regimes. After all, I don't want anyone overdoing it."

Those were the magic words -- "overdoing it." Those words ultimately saved my life. I suddenly realized that by just signing up for Buck's class, I was risking my life. After careful deliberation, coupled with the fear of permanently rearranging my anatomy, I decided to call it quits.

A week later, I was standing in Loehmann's dressing room trying on clothes when I caught a glimpse of myself in the three-way mirror. My abs were tight enough, and even if my biceps resembled walnuts instead of round, firm oranges, I was lucky to be alive, which, according to my calculations, I should be barely breathing.

Judith Marks-White shares her views Wednesdays in the Westport News and at www.judithmarks-white.com. E-mail: joodth@snet.net.