Who: Carol Gsell of Brookhaven, owner of a marketing consulting company

Her challenge: Gsell, 40, was no stranger to exercise. She's been a member of Crunch in Buckhead since 2001. While she loved the intensity of the group exercise classes, after two years she was starving for more. To Gsell — a childhood tomboy and a college cheerleader — the more hard-core, the better.

Adrienne Hughes-Harris/Special (ENLARGE)

After running around in her Gridiron workout, Carol Gsell says she's 'exhausted, but in a good way.'

Adrienne Hughes-Harris/Special (ENLARGE)

The Gridiron activities and her exercise regimen give Gsell killer abs.

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Her solution: Friends at Crunch told her about Gridiron, claiming it was the toughest class she could do. "I took it and agreed," she says. "I began taking Gridiron in early 2003, and have rarely missed a Saturday morning class since then."

A breakdown of her class: The Crunch Web site describes Gridiron as a mock football game, teaching participants to punt, pass and kick. Gsell, however, says it's actually more of an overall sports conditioning class. "It's similar to some boot camp type of classes — a lot of running, push-ups, plyometrics, jumping, obstacle courses, relays. It's different every time," she says. The Saturday morning class lasts about an hour and 15 minutes and is followed by 15 minutes of abdominal exercises.

Why it's right for her: In Gridiron, Gsell found just the "hard-core" workout she was looking for. After class she feels "exhausted, but in a good way." And the true test of an effective workout, according to Gsell? "I'm usually sore at least a little bit the next day. I think being sore means I pushed myself." Or maybe she should credit her classmates, many of whom she now calls friends: "We do everything in the class together and we all push each other when the class is at its toughest."

The results: Gsell says that, thanks to Gridiron, she feels comfortable showing her abs. And she's proud of her stamina when it comes to cardio. "I can run the Peachtree [Road Race] and Gridiron is basically training for it because we run an hour essentially. We're working so hard for an hour it's almost similar to running a 10K," she says.

Cross-training: While Gridiron may be her favorite, it's not the only workout on Gsell's schedule. Here's how a typical workout week usually goes for her:

• Sunday: Step class sometimes followed by inline skating.

• Monday: Walk

• Tuesday: Diesel class (strength training with lots of repetitions)

• Wednesday: Urban Challenge class (interval training; recently changed to Brick.)

• Thursday: One-on-one with her personal trainer

• Friday: Walk

• Saturday: Gridiron

The food factor: "My working out does allow me to enjoy food," she says. "But when I'm trying to maintain or cut back, I won't eat a late dinner. That helps me keep my weight in check." Although she admits she's not always perfect, she does generally try to eat healthy by incorporating a lot of lean meats and fish into her diet. Right after a good Gridiron workout you can probably find her at Chipotle.

Can anyone do it? "People either love it or they don't love it. We have beginners come in all the time and it's really all about attitude," she says. "It doesn't matter if you're slow. What matters is if you quit or complain or are whiny. Slow is OK. It's the effort you put into it."

Gridiron is offered at Crunch in Buckhead, 3365 Piedmont Road. 404-262-2120, www.crunch.com.