Why the Fitness in-Crowd Is Obsessed With HILIT Workouts (Boot Camp’s Kinder, Gentler Cousin)

This week on The Plus Factor, we’re talking about why more people are moving away from boot camp-style classes and favoring workouts that still keep the heart rate up, but are gentler on the body (AKA your knees will thank you).

Workout fiends have typically been divided into two major groups: the chill yogis, Pilates, and barre devotees and the die-hard bootcamp lovers who favor a high-intensity, interval training style class. (CrossFit, Barry's, and Orangetheory fans, you know who you are.) For the latter group, there's often a certain pride connected to working out so hard you that your body's sore the next day.

But slowly and surely, there's been a move away from the hurts-so-good mindset. It's likely why foam-rolling classes were trending for a while; people went so hard on their bodies that they started seeking out a way to give it some much-needed love. But let's be honest: if you're used to leaving a workout drenched in sweat, a foam-rolling class isn't going to serve as a satisfying replacement for long.

"With the rise of HIIT and the frequency people are doing these classes, they're seeing more injuries. They’re looking for alternatives that will get their heart rate up but not impact their joints." —Amanda Freeman, SLT

"HIIT was such a big thing, then foam rolling was big but people realized they weren't getting as much out of their workouts as they wanted to. So now we're seeing the trend moving toward high-intensity, low-impact with the focus being mobility and injury prevention," says fitness instructor Brookelyn Suddell, the co-director of the group fitness department at Crunch gyms. "People want to walk out of the studio feeling like they got a good workout, but also feeling good in their bodies."

"The way boutique fitness has evolved, this is the natural evolution," adds Amanda Freeman, founder of SLT, a high-intensity, low-impact workout that has caught fire in recent years, expanding from New York City to locations throughout the East Coast and Midwest. "Before boutique fitness, people weren't working out as often as they are now. Especially with the rise of HIIT and the frequency people are doing these classes, they're seeing more injuries. They’re looking for alternatives that will get their heart rate up but not put them at risk for injuries or impact their joints."

What exactly does a high-intensity, low-impact—known as HILIT—workout look like? And can it work as your sole form of exercise, or do you still need to work in cardio and strength-training days?

Keep reading for an inside look at the rise of HILIT—and what it means for your sweat sessions.

What counts as HILIT

First things, first: What exactly counts as a high-intensity, low-impact workout? According to Justin Norris, personal trainer and co-founder of buzzy Los Angeles studio LIT Method, it means you never have both feet off the ground (that's the low-impact part) and there's an emphasis on raising the heart rate (that's where high intensity comes in). "There's no jumping, no running, and no burpees," he says. No burpees? Bless up!

So what exactly do you do instead? At LIT Method, co-founder Taylor Gainor (who's also a personal trainer), says some of the core moves are inch-worming up and back into a plank position, and lots of mountain climbers. "You can burn up to 1,000 calories in a class, or 500 calories in a 30-minute class, if you're streaming a workout online," she says, driving home the point that low-impact does not mean low results. "The cardio moves are structured to raise the heart rate for 20 seconds, then dropping it back down for 20 seconds."

"You’re saving your joints for longevity, but you’re still getting into that fat-burning zone—it's the best of both worlds," Norris says.

Of course LIT Method isn't the only boutique fitness studio that's been championing the benefits of the low-impact life long before it was a trend. Celebrity trainer Bizzie Gold founded B MVMNT in New York back in 2010 with a similar ideology. "At the time, I received a lot of backlash from the fitness community, but now people have come around," she says. B MVMNT has a signature spiral structure technique, which works the core both inside and out.

"You’re saving your joints for longevity, but you’re still getting into that fat-burning zone—it's the best of both worlds."
—Justin Norris, LIT Method

"We are favoring movements that are circular, that have that deep engagement, whether that’s the deep engagement in the abdomen or the spiral motions in the shoulders or hips," she says. "The body is a round cylinder with the spine going through the center. Our core is in both the front and the back," Gold explains. "One of the best ways to work the core is to round the belly button back toward the spine and lift up so you’re getting this really exaggerated tucking and energetic lift, using arm balances to transition in and out of that tucked position to build the core and generate heat." In other words: You'll be sweating.

Like B MVMNT, SLT was in on the low-impact, high-intensity game before it was popular (since 2011 to be exact). The cardio-slash-strength training-slash-Pilates mashup focuses on one muscle group at a time and is structured to keep the heart rate up the entire time. (Entire, as in no breaks whatsoever.) The bulk of the workout is done on a Megaformer using weighted springs to really tone the body—while still protecting it from injury. "It's your cardio and toning day all in one," Freeman says.

How gyms are getting in on the HILIT game

And now, boutique studios aren't the only way to try HILIT—gyms are jumping on the trend, too. At Crunch, directors of group fitness Suddell and Marc Santa Maria both say they've added more classes to their lineup to cater to the trend. "We're really seeing the proof of concept through the popularity of the classes," Suddell says. "They are even more popular than our more cardio-based or strength-training classes."

Their cornerstone HILIT class is Zuu, which Suddell teaches. "The class has three main goals," she says. "Injury prevention, mobility, and creating community." Class goers can expect to burn between 300 and 350 calories per class, which is spent doing moves solely using body weight to spike the heart rate, and then bring it back down (over and over).

"[HILIT workouts] are even more popular than our more cardio-based or strength-training classes." —Brookelyn Suddell, Crunch

Crunch also offers bungee classes with HILIT in mind. "The doctor who created it was a trauma surgeon who worked with athletes to help rehabilitate them so they could compete again, and it’s actually low-impact," Santa Maria says. "Your heart rate goes through the roof when you're running forward, but when you spring back, you land super softly. The bungee takes the bulk of the pressure off the landing." The gym chain also just added three classes centering around a 6-pound "powerball," a translucent ball filled with weighted material, to provide stability and resistance—all low-impact, high-intensity.

At Equinox, Nicole Petitto, the brand's group fitness and barre senior manager, says gym-goers looking for a HILIT class can try out The Muse. "The program idea was born based on the desire to offer a 'true' cardio workout in the barre space that would seamlessly bridge the gap between barre and dance conditioning," she says. "The circular movement patterns integrated throughout the choreography and the overall flow feel incredible in the body and bring joy into the movement."

How HILIT can fit into the workout regimen you already have

So, do you still need your cardio or strength training days? "It depends what your health goals are," Suddell says. For the average person, she says HILIT can absolutely work for maintaining a healthy lifestyle. "If you want to build strength, muscle, or body mass, you'll want to integrate it into weight or power training," she advises. "And if you're looking to lose weight, you could integrate it into more cardio-heavy days."

Sports medicine doctor Jordan Metzl, MD, has a slightly different idea: "The best workout is whatever someone is interested in and brings a smile to their face," he says. "Because that means it's something they will do consistently."

He also points out that everyone's body is different. "Some people can train for a marathon and get no injuries at all while someone else might get injured training for a 10k," he says. "If you like the workout you're doing and you're not getting hurt doing it, keep doing it. If you are getting hurt, then you might want to think about something a little lower-impact." Besides enjoying what you're doing, the key, he says, is revving up your heart rate. "You want your heart rate to go up and down through intense bursts of short exercise," he says. "But that can be done through HIIT or HILIT. Physiologically, they can be the same."

In other words, a HILIT workout may not have burpees, but it will give you results. And hey, it's bridging fitness worlds: So if you're a boot-camp lover who's friends with a barre obsessive and a yoga teacher, here's a way for everyone to meet up and get in some pre-brunch bonding. (Because who needs more us vs. them in their life these days?)

Speaking of fitness trends, here's what you need to know about multisensory fitness . And if you have trouble fitting a workout in regardless of what type it is, steal this trick from Carrie Underwood.