Online editor Ann Limpert (alimpert@washingtonian.com) says she could happily live on pizza from Vace for the rest of her life.

My body is a wreck. My muscles--some I didn't know I had--feel shredded. I move like a turtle. It's the day after my first session with Nina Black, my personal trainer.

All my life I've had EADD: exercise attention deficit disorder. I am quick to jump on new trends--from Tae-Bo to Bikram yoga to Pilates--but I've never stuck with any method longer than a few weeks. If anything was going to make me stay with an exercise regimen, it would be a deadline--and a drill sergeant.

I'm one of the lucky people who have never had a real weight problem, and I don't particularly monitor my diet, which is loaded with carbs. I wouldn't mind losing a few pounds, but I'm mainly interested in toning up. Also, I'm a light smoker. My assignment is to see Nina twice a week for three months and continue eating as I normally would. Can you change your body just with exercise?

Nina Black was recommended by a co-worker. She's been teaching exercise in the area for 20 years. Her Web site (www.ninablack.com) boasts testimonials like "Nina Black is the best thing to happen to my body!" and "I would be lost without her!" It also says she teaches a class called "Sculpt and Torture." Yikes.

When I meet her at Definitions gym in Georgetown (1070 Thomas Jefferson Street, Northwest; 202-237-7100), she's a rush of energy--she hugs me and tells me I look great. Nina's prices vary individually; she gives me the "working-girl rate" of $65 a session.

I like Definitions, a small, usually uncrowded gym used by personal trainers and their clients. It's the least pretentious gym I've ever been to. Nobody cares if you show up in a wrinkled college T-shirt and shlubby sweats. Each session with Nina will consist of monitored weight training--no cardiovascular workout--though Definitions has StairMasters, elliptical machines, and treadmills for all the cardio anyone could want.

The first week is, of course, the hardest. I'm nervous going into the first session, and the anxiety propels me through. I work out on the leg-press machine, a weighted rowing machine, and a hamstring curl while Nina monitors things. Midway through that session, I feel faint. Nina looks at me sympathetically: "Did you eat this morning?" As usual, I've skipped breakfast. So she gives me half her lunch--a turkey sandwich from Starbucks--and a glass of water. I start to feel better. The session ends with a hug.

The next few days are hell, and when I see Nina for my second session, she laughs: "That means it's working! It's supposed to hurt!" This time the weights feel heavy, but the pain isn't bad. Nina keeps the conversation lively, which takes my attention off the weights. We talk about restaurants, movies, books, celebrity gossip, and growing up in Washington--she's a Holton-Arms grad; I'm Georgetown Visitation. We get along well. My journal entry for that day reads: "Nina Black rocks."

Over the next month, several things happen. The regimen of seeing Nina gets me eating breakfast, which makes me eat less the rest of the day. I become more conscious of what I eat--Nina is anticarb, and she winces when I talk about eating a bagel. She tells me to "picture a pile of sugar" when I see a loaf of bread or a bowl of spaghetti--"because that's all you're eating." Hard words for a bread-and-brie addict to hear, but I start trying to cut out carbs. A hacking fit during one session convinces me to try to smoke less. By the end of the first month, I've stopped buying cigarettes.

One day I come in grumbling about a killer headache--I get them a lot. Nina puts me on very light weights for the hour, and we do lots of stretching. Physical exertion has always made a headache worse, but I leave this session pain-free.

At this point, the exercise malaise is starting to set in. If I were on my own, I'm not sure I'd keep it up. Seeing Nina is a great midday release, but sometimes I just don't feel like going. And it's easy to make excuses. But I'm also beginning to realize psychological returns. I'm happy that I'm challenging myself, and I start to care not just about how I look but also about my actual health. Plus, I love hanging out with Nina--she's become a good friend. A month into this regimen, though, my body doesn't look much different.

It takes 2H months of regular sessions with Nina to notice a change in my body. One thing surprises me: I had expected the sessions to get easier, but each remains a challenge.

Each hour we concentrate on different areas--abs, back, shoulders. I've always wanted Jennifer Aniston arms, so we do lots of arm repetitions. Finally, mine start to show definition. My stomach is pulling inward, and my legs are getting stronger. There are some hidden benefits--weight training helps bone density, which is important for women.

I haven't lost weight. That would take more cardio and fewer carbs. Plus, muscle weighs more than fat. But my body's shape has shifted. Clothes hang better. I don't hate tank tops anymore. And I haven't had a cigarette in two months. Another big perk: I start getting compliments from people who don't know I'm exercising.

The downside is the cost--even with the working-girl discount, Nina is a big financial commitment--but I'm sticking with her. I couldn't do this on my own. I feel better. I'm healthier. And it's a joy to have a drill sergeant who's also a friend.