The blows rain down upon me: first a solid right to the gut that weakens my knees and loosens my bowels, then several hooks to the head. I taste metal fillings and smell the mothballed aroma of boxing-glove stuffing. I’m stumbling around, trying not to fall, when finally a voice yells "Break!" and my assailant steps back, revealing herself as a five-foot-tall woman in her early seventies.

That’s when humiliation settles in. I’m a middle-aged suburban dad, pudgy and pulsing with the bad kind of cholesterol, and I just got my ass whooped by a little old lady with white hair and matronly blue eyes. How did I end up here?

I’d wanted to learn martial arts since I was a kid reenacting Kung Fu Theatre on my parents’ couch cushions, but I never had the courage to try it, not even after my own son signed up. At a certain point, it just seemed too late. Then, one year, my wife bought me lessons as a Christmas gift, her gentle way of saying it was time for me—after a decade of babies and career and commuting and cronuts—to find a hobby, spend some quality time with the boy, and get in shape.

Three More Ways to Uppercut Your Metabolism

Whether you’re ercising the same way every time out or not ercising at all, it’s dangerously easy to sink into a rut. Your body needs new forms of stimulation. Not into the martial arts? You’ve got options.

1)** If you play basketball, try > rock climbing**.

It’s still about timing and accuracy and explosive strength, and you don’t need nine other dudes to get a pickup game.

If you lift weights, try > CrossFit. You’ve heard the stories about how tough it is. Admit it: At least part of you has always wondered how you’d fare. So go see.

If you do spin class, try > rowing**.** Rowing offers the same rhythmic churn you get from cycling, and it’s a much better total-body workout. It’s also addictive as crack.

Before my first class, I’m a veritable animal kingdom of anxiety: sweating like a pig, heart beating like a rabbit’s, petrified to be the dojo’s only 40-year-old karate virgin. But there’s no time to stew. Right away we line up, bow, and begin a series of calisthenics, stretches, punches, and kicks that push me harder than I could ever push myself in the gym. The moves have badass names like knifehand strike and hammerfist punch, and it’s all a little silly and deadly serious at the same time. I struggle at first. Even simple combinations feel weird. I’m winded earlier than I’d care to admit.

After a month or two, I start sparring. And while I’m pummeled by teenage girls, men half my size, and that old lady, by putting aside my ego (cue Morgan Freeman voice), I get better. I…im-prove. I learn to breathe. To move. To block. I move up a couple of belts. I clobber opponents my own size, age, and gender. I break a friggin’ board with my hand.

I also have a bounce in my step that I haven’t had since college, and not just because I shed twenty pounds in the first few months. For most men—of any age—fitness usually boils down to blasting your pecs or keeping your heart ticking. But it’s just as much an opportunity to expand yourself, to try something new—especially if you’ve wanted to try that thing since eighth grade but never had the guts.

Maybe for you the new thing isn’t karate. That’s fine. Any new sport this side of shuffleboard will jolt your body awake. Want to play soccer in a league but not sure you can hang? Do it. Just don’t hog the ball in the beginning. You’ll catch up. Think surfing looks fun? Take the damn lessons, and don’t worry about feeling like a rookie at first. When you’re a true beginner, you progress super fast; signing up is the hardest part. I know that now, even if it took a granny knocking some sense into me.

Luke Zaleski (@zaleskiluke) is GQ_’s Research Director. He would like to thank Sensei Jim and the other talented teachers at Fair Haven Martial Arts for their instruction, support, and patience _

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