There are tons of ?tness classes at your gym. Which ones are the best for your tennis game?

It’s 8:45 A.M. and Debbie Sutton is working up a sweat in Spencer Gee’s Monday “SpencerGize” class at Two Worlds Dance & Fitness in Greenvale, N.Y. Sutton, 47, credits the workout—a mix of aerobics, strength moves, and martial arts—with helping her stay at the top of her tennis game. “I’ve played my whole life, but I’ve de? nitely gotten much faster and stronger,” she says. A former nationally ranked player himself, it’s no wonder Gee attracts students like Sutton to his classes.

“When I played competitively,” Gee says, “I found martial arts reinforced my reaction time, improved my agility and balance, and made me more explosive on the court.” Health club schedules are ? lled with classes like Gee’s that address ?tness fundamentals. But can any of them help take your game to the next level?

“One of the top reasons people come to a class is for motivation,” says Shannon Fable, group ? tness director at Lakeshore Athletic Club in Broom? eld, Colo. Don’t feel like slogging it out on the stair climber? Try exercising in a room with 20 other sweaty bodies. Classes also help if you’re bored with your workouts, because instructors rarely repeat the exact series of exercises twice. Plus, they supplement your on-court conditioning with cross-training.

If tennis is your primary activity, some group ?tness classes will be better for you than others. Below, we answer a few key questions about which classes can help you ace your opponents.

Which ones are best for tennis?

CORE
One glance at the six pack of a top pro and it’s obvious that core strength is crucial for generating power on the court—which means ab and back conditioning should rank high on any tennis player’s priority list. But not all core classes are created equal. “You don’t want to just get on the ? oor and pound out crunches for 20 minutes,” Fable says. Instead, look for classes with a combination of exercises that mirror on-court movements, where you’re standing, lying face down, kneeling, and rotating. Bonus points if the class features tools like exercise balls for an added stability challenge.

BOOT CAMP
Sports-conditioning or boot-camp classes feature a mix of agility, power, hand-eye coordination, plyometric, and cardio drills—all perfect for tennis players. “They can be done with little to no equipment, inside or out, and they keep you moving nonstop so you burn a ton of calories,” says Jonathan Ross, owner of Aion Fitness in Bowie, Md. And don’t worry, they’re not all run by wannabe drill sergeants. “A good instructor should be both motivating and understanding,” Ross says.

YOGA
Yoga classes can help tennis players stay both strong and ?exible. Ross recommends classes like Ashtanga or power yoga, which keep you moving through a series of ?owing poses, rather than more sedate classes like Iyengar, which emphasize static positions.

What else should I try?

CARDIO
Rounding out the group ? tness offerings are cardio classes that aim to improve aerobic endurance. These classes include everything from step (great for working the glutes and core), spinning (ideal for a serious aerobic workout without any pounding), and dance (a fun way to cross train).

MARTIAL ARTS
Kickboxing gets high marks from some, like Gee, who say it enhances cardio, coordination, core strength, and balance. Others warn that inexperienced teachers may have you do repetitive motions like punches, which could back? re if you’re ?ghting off a shoulder or other upper-body injury. “If it doesn’t feel right, it probably isn’t,” Fable says

What should I avoid?

While strength training is crucial for any player, one-size-? ts-all sculpting classes don’t offer a suf? cient chal-lenge. “Look for a class that focuses on increasing strength by using bigger weights that challenge all your muscles,” Ross says. If you’re using the same weight to work your arms, shoulders, chest, and back, you’re not getting the workout you should.