We're often going on about the benefits of breaking out of your workout comfort zone. While that idea sounds great on paper, it isn't always so easy in practice. Trying out a new fitness class can be a bit daunting—you're exposing yourself and your body to something entirely new, not to mention just showing up can be quite intimidating. One particular workout that's gained somewhat of a cult following but whose name alone is enough to make beginners wary is HIIT—or high-intensity interval training, and we know all about it, thanks to fitness expert Rob McGillivray.
Meet the Expert
A week after my first HIIT workout, once I had finally caught my breath, we had McGillivray give us the lowdown on everything a first-timer should know about HIIT. He patiently explained everything from how to best prepare for the class, to what you're up against during a session, to what results you can expect to see moving forward.
So, if you're interested in taking on a HIIT workout, here's everything you should know before getting started.
What Is HIIT?
I must admit, before taking my first HIIT class, I had little knowledge of what exactly I was in for. "High-intensity interval training" could lend itself to quite a few exercises. Still, McGillivray explained that essentially it comes down to "a set amount of time on a piece of equipment" (interval training) with the goal of "raising and lowering your heart rate." In other words, rather than working out at a constant, moderate effort as you might when you go for a jog, you complete bouts of hard effort work interspersed with short periods of rest. McGillivray admits that the first part of the name—high intensity—"can have a little bit of an intimidation connotation," but he encourages first-timers to look past that.
Why HIIT Is a Total Body Workout
"HIIT can be segmented, but I think for a more well-rounded, workout you want to encompass the body as a whole to keep it as balanced as possible, hitting every major muscle group at the same time," says McGillivray.
Each gym might put their own spin on just how they set up their interval training, but at RETROFIT, McGillivray explains that the trainers program their circuit "so you're getting a total body workout in every class—you don't just show up on Monday and do chest and arms."
Even the cardio equipment at RETROFIT forces you to switch up which muscle groups are working at each station. "We wanted to have the variety and versatility in the equipment provided both in the resistance portion of the workout and the cardiovascular portion," notes McGillivray.
Not only does such variety keep workouts fun and engaging, but it maximizes the effectiveness of the workout. Even if you don’t have the luxury to attend a class at McGillivray’s facility, the HIIT classes or workouts you take on should target all major muscle groups and involve compound, full-body movements like burpees and squats. You can also expect a heavy dose of cardio exercises such as running stairs and pushing through sprints on a bike. One thing that makes HIIT a total body workout is that it simultaneously challenges your cardiovascular and muscular systems.
The Benefits of HIIT Workouts
Numerous studies have found that the HIIT torches more calories per minute than steady, moderate exercise. "You're working at such a rate that your body is crushing food," explains McGillivray. "You've got the ability to burn an exceptional number of calories in a very short space of time." He notes that with HIIT, you can burn anywhere from 500 to 1200 calories (depending on the intensity and specific movements). As opposed to the 200 or 300 calories you might burn at the gym just focusing on a couple of body parts.
It increases your metabolism.
The good news on the calorie front doesn't stop there. Because your body has to work especially hard to get rid of the metabolic byproducts (think lactic acid) generated during the workout, return your heart rate to resting levels, and repair and replenish your muscles, you continue to burn additional calories at rest even once the HIIT workout is over.
It increases your endurance.
Marathon runners take note. Although you might think that a long run—or any continuous bout of exercise at a constant, moderate effort—would be the most effective way to improve your endurance, research has found that training programs that rely on HIIT workouts result in greater improvements in cardiovascular endurance and aerobic performance compared to steady-effort sessions. Even if you don’t have plans to sign up for the next marathon or ride your bike for several hours, this is still good news. If your endurance improves, your workouts will start to feel more manageable, and you’ll be able to exercise longer.
It improves your overall health.
HIIT training has been shown to lower blood pressure and blood sugar and improve markers of health. A 2015 study demonstrated that it’s also effective at reducing abdominal body fat, specifically linked to diabetes, metabolic syndrome, and cardiovascular disease. In the same study, HIIT training also improved insulin sensitivity and lowered blood lipids. While all these findings are especially favorable for individuals with diabetes; they are also beneficial outcomes for those without any chronic health conditions.
It can be done anywhere without anything.
HIIT workouts are extremely portable. You can do them in a class like those at RETROFIT with various equipment and machines. But, equally effectively, you can do a HIIT workout at the park, at the track, in a pool, on a bike, or in your living room with nothing but your body weight. The options are limitless. The only requirement is that you jack up the intensity, spike your heart rate for intervals of anywhere from 15-60 seconds (though some other durations may be used), and then follow those high-intensity surges with low- to moderate-effort recovery periods.
It’s “come one, come all.”
Though HIIT may sound daunting, it’s not just reserved for advanced athletes. Even if you’re just starting your fitness journey or haven’t been consistently working out for a long time, HIIT training can be safe and appropriate for you. Work within your current fitness level and comfort zone. For example, you can do a walking HIIT workout. After a comfortable five-minute warmup walk, alternate intervals of 45 seconds of brisk walking (at an effort level of 7-9 on a scale of 1-10) with 45 seconds of easy, recovery walking (at an effort level of 3-4). Complete 10 rounds and then cool down with five minutes of slow walking. As your fitness level improves, the speed you must walk for your intervals will increase in order to hit the target intensity. You can also increase the length of time for the high-intensity efforts, shorten the rest bouts, or add additional rounds.
How to Prepare for a Class
"I would say fully hydrate and bring a spare T-shirt for after," McGillivray advises. "I think the most important thing is coming in with an open mind, not to feel intimidated by the terminology of the class—the high-intensity aspect of it." He assures us that beginners need not feel intimidated; you’ll be able to work at an intensity that’s appropriate for you. "It's supposed to be just as much a fun experience as it is supposed to be a diverse and effective workout," says McGillivray.
What to Eat Before and After a HIIT Class
McGillivray advises having some food in your stomach before coming in. "Even if it's just a small snack—a small package of nuts 45 minutes to an hour before a workout." He notes how this is especially important for individuals who are not as regular with their exercise or are getting back into a routine after not working out for a while. "It is really important to give your stomach something to work on—without filling your stomach—to give you energy," he notes, explaining how it helps curb the acids that will begin moving around.
McGillivray also says to make sure there's consistency with the hydration—"not overloading yourself with water where it feels like you're bubbling over with fluid during the workout but still making sure you're not dehydrated." This is especially important for beginners. "If you haven't done that kind of exercise before, you'll feel that buildup of lactic acid quite quickly," he notes, and these hydration measures will "help the body detoxify."
Post-workout, McGillivray suggests a protein-packed smoothie to help restore the body and restore the body.
How to Customize Your HIIT Workout
"In each system, you can push yourself to the level you feel comfortable with," explains McGillivray. "It's on the individual themselves if they want to push to a certain level of comfort or ability. Even if the buddy next to them is going full, all-out, you can still go to your own body's ability level." The short intervals and spurts of exertion also help each individual to work toward their goals. "By breaking it down into stations the way we do, even if you hate a particular station, you only have to do it for that 60 seconds, and you're onto the next," notes McGillivray. "Anybody can do anything for 60 seconds."
These same principles should apply with whatever HIIT class or workout you take on, whether at RETROFIT, another fitness studio, or streamed online at home. “Intensity” is all relative. Your high intensity and another person’s high intensity are the same in terms of how they feel to each of you (hard!). Still, the actual weight you’re using, or the speed your running, or the number of reps you perform in the interval is unique to you and your fitness level. HIIT workouts are customizable to each individual, so even beginners can take them on with confidence.
How to Make Working Out More Fun
"There are a lot of people who find it more of a chore to come to a gym or go to a class [but do it because] they know they have to for their health," observes McGillivray. "We're trying to put the enjoyment back into these classes." His studio builds off of the idea of camaraderie, with every station set up to be done in pairs of two. "There is that worry going into a class format that it's going to be this extreme, insanity workout," he says. “But, when really experiencing it, you realize it's less about being competitive and more about being a part of a community.”
McGillivray suggests enlisting a friend to take a HIIT class with you or to hit the park for bodyweight exercises and sprints together in order to make the workout more fun and motivating. "Bring a friend or meet someone there to become your exercise buddy. You can help push each other through the workout," he says.
Even if you’re all by yourself in the quiet of your studio apartment, you might be surprised about how fun HIIT training can be. The inherent variety created by the intervals keeps the workout engaging. It’s gratifying to set goals, push yourself, get your heart pumping, and tackle the challenge of a HIIT workout. Just don’t blame us if you get hooked.
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Niamh J. Ní Chéilleachair, Andrew J. Harrison & Giles D. Warrington (2017). HIIT Enhances Endurance Performance and Aerobic Characteristics More than High-Volume Training in Trained Rowers. Journal of Sports Sciences, 35:11, 1052-1058.
Shepherd SO, Wilson OJ, Taylor AS, Thøgersen-Ntoumani C, Adlan AM, Wagenmakers AJM, et al. (2015) Low-Volume High-Intensity Interval Training in a Gym Setting Improves Cardio-Metabolic and Psychological Health. PLoS ONE 10(9): e0139056.