Get the lowdown on the workout style everyone’s doing to get fit in less time.

From at-home routines to gym classes, high-intensity interval training (HIIT) workouts are everywhere right now, and rightfully so. Short spurts of intense cardio and strengthening exercises, they’re incredibly efficient—the perfect routine for busy women. No wonder high-profile women such as the Duchess of Cambridge Catherine Middleton, Reese Witherspoon, Jessica Biel, and Jennifer Lopez are HIIT loyalists. But if the name alone has you assuming this workout isn’t for you, here’s what you should know.

What Is HIIT?

HIIT stands for high-intensity interval training, a form of training that incorporates short but intense cardio and aerobic exercises in between less intense recovery periods. HIIT drills crush calories in little time and have the same cardiovascular health benefits of longer workouts. Health and fitness researchers call the "bouts of high-energy exercise with low-effort rest intervals" the "burn-and-recover cycle." Physical therapist Kadeem Howell of Physiofitness shares with Verily, “HIIT workouts are proven as one of the most effective ways to decrease body fat with an average calorie burn of up to 360 to 480 for a thirty-minute session." And unlike endurance cardio, you lose fat and build muscle tone at the same time.

Designed to work multiple muscle groups at a time, HIIT routines are full-body workouts for even toning. Better yet, your metabolism stays high even after a brief HIIT routine, continuing to burn calories throughout the day. “Your body continues working for hours even after a 20-minute session is over, due to what is known as excess post-exercise oxygen consumption,” explains Viva health coach Richa Pasad.

HIITing Has Its Risks

Before you start to plank like Reese or lunge like J.Lo, beware the risks of extreme exercise. High-intensity workouts can occasionally cause painful and severe conditions like rhabdomyolysis, which is when your muscles start to die and leak into your blood. A report in the American Journal of Medicine investigated various cases of people who developed rhabdomyolysis after taking spin classes. To avoid injury, read these tips from fitness experts on how to HIIT it off on the right foot.

6 Ways to Make HIIT Work for You

01. Realize it’s not a quick fix to get in shape.

Intense HIIT routines are not for exercise newbies. If you’re just starting to work out regularly, choose more traditional cardio or a lighter HIIT regime. As Olympian official for W8 Lifter USA Robert Herbs tells Verily, “Celebrities probably have had a personal trainer for years. The average woman can't jump right in, but must first get into shape with some basic strength, conditioning, and flexibility work.”

02. Keep it to one to three HIIT workouts a week.

Do not do HIIT daily. The harder you work out, the more time your body needs to recover. Your joints especially need to rest to prevent over-straining from the repetitive motions. Fitness professional Jessica Zapata at Infinite Fitness told us, “A beginner should start with only one HIIT workout a week, while twice a week for your average person is plenty.”

03. Balance HIIT with lighter cardio and strength training.

On non-HIIT days, choose a low-impact cardio workout like swimming, jogging, biking, or speed-walking as well as strengthening exercises. Orthopedic surgeon Dr. Benjamin Domb tells us, “Strengthening the muscles around joints that receive the most impact during HIIT workouts including the knees, hips and back will help protect them by providing extra support. Leg extensions, hamstring curls, and partial squats are all excellent for joint protection.”

04. Do thorough warm-ups and cooldowns.

It’s easy to forget the oh-so-critical stretching and mobility exercises before and after a grueling workout. Howell's top advice is to “Make sure to do your own due diligence and focus on treating your injuries with warm-up mobility exercises such as foam rolling, dynamic stretching, dynamic running drills, and newly popular Kinstretch exercises.”

05. Learn from a personal trainer or class.

Sign up for a class or work with a trainer to ensure that you’re learning the proper form and technique. “Once you are confident that you are no longer a beginner, feel free to move onto more advanced exercises and classes. But make sure you start at the bottom and work your way up,” recommends personal trainer Richard Wilcock of Flagship Fitness.

06. Listen to your body.

Don’t punish your body with a too-intense workout. Push yourself to keep improving, but be patient and let your body adjust. Pasad suggests, “If you find your performance actually decreasing session by session, it may be a sign of overtraining and you may need to scale back the intensity, frequency, and duration, or increase your quality sleep.” We need to exercise because we love our bodies, not because we hate them. So pace yourself.

And of course, stay hydrated and eat well to sustain your body throughout your HIIT sessions. You may not snag headlines like the sporty Duchess of Cambridge, but you can improve your health without a long gym session, which is something anyone can aspire to.

Photo via Celeb Mafia