If an Orangetheory Fitness hasn’t yet popped up in your neighborhood, chances are, it’s likely not long before it moves in. The boutique fitness franchise has over 860 open studios, with 771 in the United States alone. Compare that number to the (significantly fewer) 82 studios SoulCycle has within the States and Canada, and it seems like a new fitness method has officially overshadowed the cult-like, dance cardio cycling conglomerate.

Head to the Orangetheory Fitness site, and you’ll be transported to a home page featuring high-res videos of individuals who are the definition of #fitnessgoals accompanied by bold claims, like the workout itself is scientifically proven to give you a longer, more vibrant life, and will armour you with increased energy, greater strength, and better fitness results.

With promises of a stronger body and a better life, Orangetheory seems like the ideal workout. But what actually happens during a 60-minute class? And do these claims actually hold up IRL?

We dug into the science behind the interval-based workout franchise to find out.

What to Expect

The makeup of an Orangetheory Fitness workout studio isn’t incredibly different from what you might see at a Barry’s Bootcamp or another interval-based workout class. Treadmills line the front of the room, and a few feet behind them are columns of indoor WaterRowers. Directly in the center of the classroom is open floor space featuring fitness equipment—like dumbbell tracks, TRX bands, and BOSU trainers. Several miscellaneous stationary bikes and strider machines are positioned on the outskirts of the treadmill wall.

What is noticeably different is that upon walking through the front door, a heart rate monitor gets fastened on my right arm, right below my elbow. (Usually, gyms just offer complimentary ponytail holders.) That’s because Orangetheory’s entire concept— er, theory —is based on the science of excess post-exercise oxygen consumption (or EPOC).

The Workout

Harnessing the technology of real-time heart rate monitors, the signature Orange 60 class brings you through five zones of interval training. (For reference: Zone one, or the grey zone, signifies ‘very light activity’ and requires 50 to 60 percent of your max heart rate. Zone Five, or the red zone, signifies ‘all-out effort’ and requires 92 to 100 percent of your maximum heart rate.)

Using the equipment listed above, coaches lead a workout that challenges you to push yourself to intensities of 84 percent of your maximum heart rate (or zone 4: the sweet spot of the orange zone, or ‘uncomfortable’ effort) or higher for at least 12 and up to 20 minutes of the class. By achieving this threshold, Orangetheory’s program design claims to leave visitors with an ‘afterburn effect,’ or an increased metabolic rate (think: you’ll have extra energy and burn more calories), for up to 36 hours after exiting the classroom.

How each person reaches the orange or red zone is entirely up to how hard and how far they are willing to push themselves. Every workout is different, but each class follows more or less of the same protocol that leaves little opportunity for failing to raise to your heart rate: Thirty minutes are spent on a treadmill completing intervals alternating between varying levels of speed, recovery, and hill training; the second half of class is spent splitting your time between strength training exercises on the floor—think: weighted squats, overhead presses, burpees, and more—and time doing work atop a WaterRower.

If you’re feeling a bit overwhelmed, that’s OK—the complexities of the workout are what make it so effective. Luckily, an instructor will guide you through every interval, equipment change, and recovery minute, and a large-screen positioned in the front of class displays your heart rate and “splat points”—or the points you receive for every minute spent in the orange or red zone—so you can focus on what you’re there to do: work.

The Benefits

OK, so the variation of treadmills, intervals, WaterRower sprints, and strength training combined with the additional challenge of maxing out your heart rate definitely makes Orangetheory sound like a workout worthy of your time. But is it worth $35 for a single class (New York City Chelsea’s studio drop-in rate)? Note: Prices for classes vary based on region.

Here’s the argument for, “Yes.”

1. The workout is scalable.

One of the perks Orangetheory uses to incentivize newcomers is that the workout is suitable for all levels of fitness. Class-goers have the option of power walking at an incline during treadmill intervals if they aren’t comfortable going faster, and classrooms also have stationary bikes and striders if running just isn’t an option.

Instructors also help with modifications during strength training exercises for those who have injuries or restrictions.

2. The technology keeps you accountable.

When we’re alone at the gym, it’s easy to let our mood, attitude, or outliers (too little sleep the night before or a looming deadline at work) affect our perception of how hard we’re actually working. I’ve also been guilty of withholding effort (read: half-assing) group training sessions just because nobody will call me out on it as long as I’m still going through the motions like everyone else.

With the integration of OTbeat, Orangetheory’s exclusive heart rate monitoring technology, individuals are able to see real-time feedback on how hard they’re working. For the right client, the knowledge of what they’re currently exerting paired with knowing what they have left in the tank can be incredibly motivating.

“OTbeat holds you accountable,” says Alexa Javens, a coach and regional fitness and operations manager of three Orangetheory studios in Brooklyn. “Staying within a certain heart rate zone and maximum heart rate percentage prevents the chance of undertraining—or overtraining—within the hour.”

3. The workout is personal.

“It’s usually more difficult for more active people to reach the orange zone,” Javens warned me as she gave me a quick-and-dirty rundown of the workout pre-class (this is a prerequisite for all new studio-goers).

She was right. I had to fight to push myself on the treadmill in order to break into the orange zone, working harder than I typically do, say, at Mile High Run Club or Barry’s Bootcamp. Yet around me, other class-goers were moving at varying paces—from power walking on an incline to all out-sprints—to achieve the same outcome.

Since your maximum heart rate is unique to you (it’s individual and depends on your age, weight, and activity levels), that means everyone in class must work at a different rate to break into the orange zone, making the workout personal and unique to your specific needs.

4. You’ll target multiple muscle groups.

By incorporating a variety of machines, fitness equipment, and exercises into 60 minutes, you’ll get a high dose of cardio while targeting multiple muscle groups.

“Every Orangetheory class is a full body workout,” Javens explains. “We never focus on muscle overload for one specific muscle group.”

5. You could burn up to 1,000 calories per class.

Orangetheory estimates that, based on earning 12 to 20 splat points per class, gym goers will burn anywhere from 500 to 1,000 calories during class. Compared to SoulCycle’s estimated 500 to 700 calories burned per class, there’s a nice window of opportunity for additional burn.

Of course, these are estimations coming directly from each brand, so take those numbers with a grain of salt (or side eye, if you will). While there’s no real guarantee you’ll burn a certain number of calories, the workout summary report Orangetheory emailed me directly after class estimated I personally burned 565 calories and earned 11 splat points—which, for the hard work I put in during those 60 minutes, felt accurate.

6. It’s backed by science.

Though mentioned earlier, it’s worth repeating. Orangetheory’s heart rate-based interval training workout centers around the science of excess post-exercise oxygen consumption (EPOC). Designed by renowned physiologist Ellen Latham and backed by Orangetheory’s own medical advisory board, 12 to 20 minutes spent in the ‘orange zone’ throughout class can help you burn more calories for up to 36 hours after class.

Compare that to the 14 hours of increased metabolic rates studies show cyclists benefitted from after a 45-minute workout, and you can see how Orangetheory’s method pushes the number to nearly double.

The Real Deal

Orangetheory may, in theory, sound perfect. But there are a few things you should know before signing on for an Orange Premier membership (unlimited monthly classes).

1. Orangetheory is a franchise.

Individual Orangetheory Fitness studios and gyms are part of a franchise, which means while all locations are all technically run underneath the same umbrella, each studio is managed differently and may have a slightly different vibe, crew of coaches, and customer service style.

Trying to reach out to the corporate customer service proved troubling for me, but after contacting the Williamsburg studio directly, I had a much easier experience.

2. It’s not personal training.

Certified personal trainer and host of Hurdle podcast Emily Abbate believes Orangetheory is a great workout that breaks down many of the barriers to fitness newcomers face—yet she cautions those who are brand-new to fitness from jumping right in without doing any homework.

“At Orangetheory you have the opportunity to be coached, but that coach won’t be holding your hand every step of the way,” Abbate says.

Since technical strength training moves are a big bulk of what Orangetheory offers, there’s definitely room for poor form and wrongful executions to slip through the cracks (during my own session, confusion during my floor portion delayed the workout until the coach was able to address our concerns).

“People who are looking for that personal training experience should know that if they really want personal training experience, they’ve got to get one-on-one coaching—there’s no inexpensive way to get those same results.”

3. It might not help your marathon training or weightlifting PR.

Orangetheory is a great workout to improve or maintain your current fitness levels, says Ash Kempton, a certified personal trainer based in Golden, Colorado, In fact, she believes it may be the best workout you can do if you have an hour of time, several days a week! But it’s not for everyone.

“Where it gets tricky is if you are an athlete with a specific, non-weight-loss goal in mind, such as marathon running or bodybuilding competitions,” Kempton says. “While these types of athletes would benefit from high-intensity interval training, like OTF, they must remember to balance it with their sport-specific work, such as distance running or heavy lifting. For example, you probably shouldn’t show up to the start line for 26.2 miles by only going to OTF, but you will go faster by incorporating OTF a few times a week into a typical marathon training cycle.”

The Conclusion?

No workout is perfect, but my experience at Orangetheory definitely challenged me and motivated me to work harder than I usually do in a group training session.

My take? Trust the science and try out a class for yourself.