And in This Corner

If you don't believe me, try shadow boxing (throwing punches in the air) for three minutes and see how tiring it is.

Boxers are usually the best conditioned athletes in the world, and training in that kind of environment tends to rub off on people.

A Brave New Ring

Punch Fitness in Deerfield Beach, Fla., is a good representative of the new wave of boxing gyms.

Clean and modern, Punch offers members the kind of gym environment they're used to, along with kick-butt classes (and the opportunity for a real butt kicking, if one is so inclined).

Members at Punch, 65% of whom are women, take boxing conditioning classes -- taught by former contender Kenny Lunkin -- along with others like cardio kickboxing and abs/kickboxing.

And while pounding the bag, don't be surprised to see junior welterweight champ Miguel Cotto or No. 1 heavyweight contender Sultan Ibragimov firing off combinations next to you.

Charles King of King's Gym in Oakland, Calif., marvels at how things have changed.

"Back in the day, you were either a fighter or not," he says. King remembers when white-collar clientele were afraid to come to a boxing gym, especially one located in a rough neighborhood. "Now they all come. Accountants, lawyers, they're all here."

King estimates that less than 10% of his members are bona fide boxers.

"A few get in the ring to spar, but most don't," he states.

While breaking a sweat at King's, you could find yourself watching Olympic gold medalist and professional prospect Andre Ward going through a similar routine.

Class in Session

Once you've realized that a boxing workout is a great way to get in shape, think about whether you want structured classes or access to trainers.