EVEN THOUGH I DON'T HAVE many aerobics classes under my belt, I've always been curious about those TV exercise programs: Are they basically the same? Would they give me a good workout? Motivate me? Make me pine for Jack LaLanne? One week recently, I decided to try them out.

All of 'em.

I bought a TV Guide, marked all those that looked like exercise programs (hesitating at "Quantum Leap"), set my alarm for 5:15 and went at it. By the end of the week, I'd stepped, stretched and strengthened with 10 different programs, at one point for two and a half hours straight. Clearly, they're not all alike:

5:30 a.m. - "Homestretch," KCTS. "Oh good," I thought, "I get to start with stretching." No such luck. This basic exercise program - the only one for folks without cable - features aerobics and strength training. Although one show was supposed to emphasize "gluts and abs" (rear-end and stomach muscles), I quickly felt another body part that gets a workout with TV exercise shows - the neck, from turning to watch what the leader is doing.

6 a.m. - Four choices: "Bodies in Motion" (ESPN), "Tamilee Webb" (Cable Health Club on The Family Channel), "Body Moves" (CHEK) and "Mousercise" (The Disney Channel). The latter two aren't on my cable system (Summit). "Bodies in Motion" is distinguished by the setting, a Hawaiian beach, and by the instructor, Gilad Janklowicz, who manages to shout the entire half hour. Perhaps he's yelling over the sound of the surf. He leads a vigorous workout, and through the week I came to appreciate the clear directions, tight production and even the yelling, which kept me awake.

6:30 a.m. - "Getting Fit with Denise Austin" (ESPN) and "Body by Jake" (Cable Health Club, The Family Channel). I'd rather eat breakfast. Austin seems knowledgeable, but her perky, cliched running commentary could drive me to quit exercising. "Do you want to trim your legs and get sexy thighs?" she coos. Well, not really. The camera work is spotty, sometimes panning off her feet just before a change in steps. As for Jake Steinfeld, as likable as he may be, I can't imagine waking up each morning to a guy who refers to the gluts and abs as "the buttisimo" and the "aba-dabas."

7 a.m. - "Step Reebok" (ESPN) and "Stylin' Aerobics" (Cable Health Club on Prime Sports Northwest). The industrial scaffolding and dramatic uplighting of "Step Reebok" can be intimidating, but these are solid, no-nonsense step workouts supplemented with strength training. I liked the ones led by Gin Miler, who is both precise and funny without trying too hard. "Stylin' Aerobics" is my name for the dancy Cable Health Club session led by two woman named Petra and Avian. They encourage a good dose of attitude ("stylin' "), which makes it fun even for a dance dolt like me.

7:30 a.m. - "BodyShaping" (ESPN), "Everyday Workout" (Lifetime Channel), "Body by Jake" again (Prime Sports Northwest) and "Work It!" (KCKA, KBTC). My cable doesn't offer the last one. "BodyShaping" is primarily for strength training, and I wonder how many people follow along, lifting weights while watching TV. The "Everyday Workout" was the most low-key show, just one woman (Cynthia Kereluk) in a room with wicker chairs, Persian rug and French doors, softly talking me through a safe, gentle workout.

8 a.m. - Another "Everyday Workout" (Lifetime Channel), different from the 7:30 one.

8:30 a.m. - A break! Breakfast, perhaps?

9 a.m. - "Body Moves" (BCTV) and "Sit and Be Fit" (KCKA, KBTC). I get neither program, which after doing all the earlier shows made me appreciate, for once, not receiving more cable channels. Though I hear "Sit and Be Fit" offers a nice workout for older or disabled people, akin to the "Chair Dancing" video I reviewed here last month.

2:30 a.m. - For East Coast early risers ESPN offers "Fitness Pros," a group of trainers taking turns in the lead; their banter is mildly entertaining and the workout better than average. However, I wouldn't recommend going to sleep, getting up at 2:15, doing the workout and then trying to get back to sleep again at 3. Trust me.

My top picks? Gilad, "Step Reebok" and "Stylin' Aerobics." Though I still have some doubts about letting other people plan, guide and monitor my regular exercise, I'd consider trying those three again.

Next time, just not all at once.

Molly Martin is assistant editor of Pacific.