New High Intensity Workouts to Try

FOR WOULD-BE ACROBATS: JUKARI FIT TO FLY

This aerial workout will make you feel like you're training for the circus, thanks to Reebok's collabo with Cirque du Soleil. Using a specially designed trapeze-like apparatus that's suspended from the ceiling, the workout mixes in-the-air movements with mat exercises. "This is a good class for everyone, no matter your fitness level," says Leslie Calvagne, Reebok's training director for Jukari, who created the workout. "Because of the design, you control the difficulty level."

THE UPGRADE: While some of the moves are borrowed directly from Body Bar strength training and pilates, the difference with this class is that you'll be having too much fun to realize you've just done 30 reps.

TIME COMMITMENT: One hour

CALORIE BURN: Equivalent to a six-mile run

SIGN UP: Currently in Boston, L.A., and New York; more cities planned for fall (reebok.com)

FOR ASPIRING SNOWBOARDERS: INDO WINTER BOARDING

Think of this class as a dry run before hitting the slopes this winter. The instability of the Indo Board (basically, a skateboard on a removable balance cushion instead of wheels) strengthens and defines legs. Expect an intense quad workout because of the emphasis on squats.

THE UPGRADE: "It's similar to the Bosu ball because they're both balance trainers, but the Indo Board surface is much more unstable, so you have to work your lower body harder to stay up," says Terrell Pruitt, Indo Board instructor at Crunch.

TIME COMMITMENT: One hour

CALORIE BURN: Up to 500

SIGN UP: Available at Crunch gyms in Miami, Chicago, San Francisco, and New York, with more cities planned (crunch.com)

FOR SPIN-CLASS JUNKIES: REALRYDER

This workout is done on an indoor bike that handles like it's on the road—tilt-technology allows the bike frame to move freely, mimicking the steering and leaning you'd experience cycling outdoors.

THE UPGRADE: "Stationary bikes are only peddling simulators," says Colin Irving, competitive cyclist and cofounder of RealRyder. "Instructors can now incorporate leaning—like you're going around a turn—which will instantly bring your core muscles and upper body into the exercise."

TIME COMMITMENT: 45 minutes

CALORIE BURN: 100 more than you'd work off in a typical 45-minute Spin class

SIGN UP: Classes are available at 74 gyms across the country (realryder.com)

FOR KICKBOXING GRADS MIXED MARTIAL ARTS

Reap the fitness benefits of a full-contact combat sport without the bruising. At L.A. Boxing, the Mixed Martial Arts (MMA) Workout combines kickboxing with other martial arts moves and is practiced only against a heavy punching bag—not your gym buddy.

THE UPGRADE: "You're getting everything you would in kickboxing, but it's more cardio-vascular," says professional MMA fighter and director of instructor training, Benji Radach. "It's pretty much a full-body, kick-your-butt workout. You'll see results much faster."

TIME COMMITMENT: One hour

CALORIE BURN: Up to 800, depending on how hard you're willing to work

SIGN UP: Don't let the name confuse you—L.A. Boxing gyms are located in 21 states (laboxing.com)

FOR FIT YOGIS: YOGAWORKS SLIM

It's tree pose meets interval training. Created by YogaWorks, an L.A.-based yoga school, Slim combines fast-paced sun salutations with slow-burn moves to sculpt legs, arms, and abs.

THE UPGRADE: "This class is designed for people with past yoga experience who are looking to fill a void in their routine without having to go join a separate gym," says Julie Kleinman, VP of programming at YogaWorks. "It's an all-in-one workout—you get the mind-body alignment and the weight loss."

TIME COMMITMENT: One hour

CALORIE BURN: 300 calories

SIGN UP: Available at YogaWorks studios in September (yogaworks.com)