Heart-rate training is backed by an impressive amount of science and it really can be the key ingredient for fitness success. That's why many fitness studios use heart-rate training as the basis of their workout programs -- but one studio in particular has a massive nationwide following due to its supposed effectiveness.
The first Orangetheory Fitness (OTF) opened in 2010 in Fort Lauderdale, Florida, and nine years later, the company is still opening new locations all over the country. The founders of OTF call it the "multi-vitamin of metabolic training" and say that everything OTF comprises is what you need to "burn fat at the highest level."
Here's how it works and why it might be the key to torching body fat.
The 'theory' behind Orangetheory Fitness
OTF is based on something called excess post-exercise oxygen consumption (EPOC), a concept that refers to your body's increased intake of oxygen after physical activity. It's colloquially referred to as the "afterburn."
The afterburn effect occurs after any sort of strenuous activity, but some research suggests that high-intensity training produces the longest-lasting and most significant EPOC. OTF uses a strategy comprised of five training zones:
During a one-hour long OTF workout, the goal is to spend at least 12 minutes in the orange zone (zone four) or in zones four and five combined. For each minute you spend in the orange zone or higher, you earn one "splat point."
OTF measures your splat points using OTbeat, a chest-strap monitor that measures your heart rate. Members can see real-time data during the workouts, which can enable them to push harder and reach the coveted orange zone. The connected OTbeat fitness app tracks results and progress over time.
OTF claims that earning all 12 splat points will result in an increased metabolic rate for up to 36 hours post-exercise.
What's the orange zone and why is it important?
The orange zone is simply OTF's designation for the 84% to 91% range of your max heart rate. It's the basis for OTF training because that 84% mark is supposedly the point at which your body starts to burn fat more efficiently and helps EPOC kick in.
So, does it really work?
Yes and no: Science is hardly ever black and white. The answer is yes, OTF works because the workouts are intense. They jack your heart rate up and work your whole body -- everything a workout should do when you're looking to get in and out in an hour.
You can certainly burn a lot of calories during OTF. The company says participants will burn an estimated 500 to 1,000 calories each class.
But the answer is also no, or perhaps not as well as OTF and its evangelists makes it seem. Getting all 12 splat points can definitely produce some EPOC and keep your metabolism burning faster after the workout. But the actual scale of those benefits is tiny, and the 36-hour idea is definitely a stretch: Research suggests that no matter the type of exercise, oxygen consumption is only greater for about an hour after exercise.
Research on EPOC and extra calories burned after exercising varies greatly. For instance, scientists have found study participants to burn as many as 190 extra calories over 14 hours following a workout and as few as 12 extra calories.
In fact, studies that compared high-intensity training, sprint intervals and continuous steady-state exercise have found that the oxygen consumption values for each exercise modality don't differ much. That means you could essentially get the same results (as far as EPOC is concerned) by doing OTF or slowly jogging a few miles.
There are no clinical trials that examine OTF specifically for its effects on EPOC or metabolism. So while the training concept is based on valid science, there's currently no definitive evidence to support OTF's claims, especially the 36-hour thing. Even the study that showed 14-hour EPOC had participants exercise at an intense level for a full 45 minutes. During OTF, you only aim to reach that level for 12 minutes.
Science aside, OTF works because it's fun. It's high-energy and the classroom environment is motivating. The workouts also vary, so it's hard to get bored with OTF. Plus, you can get drenched in sweat in just one hour, which is often hard to do when you go to a traditional gym by yourself.
It also caters to all fitness levels. The studios offer three different levels: Walking, jogging and running. All three are designed to help people of different abilities reach the orange zone, so you can achieve the coveted afterburn whether you're a total beginner or a fitness call regular.
Additionally, many people find success with OTF because they can stay consistent with it. And the best workout is always going to be the one you can stick to.