The other element of the class that has absolutely nothing to do with eggnog's effect on your backside? "What's different about Holiday Combat is it focuses on gearing the members up for the holidays, particularly if they get stressed out with travel arrangements, Christmas gifts, cards, relatives coming in, parties, planning, all that stuff," explains Marc Santa Maria, New York City's regional director of group fitness. "We'll give the members something to do outside of the classroom. It might be to go for a walk or go dancing, or doing something specifically for the holidays, like 'Start booking your plane tickets.'"

This "homework" idea came from Crunch's Bikini Boot Camp, which Santa Maria helped create earlier this year. "We were inspired by how it unified members when they were laughing over some of the things they did outside of class," he says, and that camaraderie brought people back each week, too.

Okay, Grinches probably won't get the most out of this class (though a lot of the holiday talk is tongue-in-cheek), but there's a practical benefit to a 12-week regimen, particularly when the cheese logs and sugar cookies (mmm... cookies) start appearing at the office. "It is enough time that you can actually see some results," Santa Maria says. "If it were a month-long program, you might not see results. If it were longer, you might lose interest."

As the weeks go on, Holiday Combat will shift gears, from a sculpting class with a few fat-burning moves to an even cardio-sculpt balance. If you're not training for a sprint to get the last Elmo (or whatever the toy of the moment is this year) at Toys "R" Us, it at least ought to lessen the impact of a second helping of mashed potatoes.