CHAPTER SIX

Fun and Fast: Eight Basic Workouts

I design my own workouts all the time. I go down into my basement, hop on the exercise bike, turn on some sports on the television, and get to it. Sometimes I’ll perform various bodyweight exercises between sprints. Push-ups, pull-ups, burpees—you name it. Each of these amounts to strength-building resistance training that will help me stave off the effects of aging. Creating workouts is one of the fun things about exercise. It keeps things fresh.

This chapter is all about providing people with the tools to create their own high-intensity interval training workouts. The difference between these workouts and those in most other exercise books is that the benefits of these programs have been scientifically proven. Below, I include eight workouts that have been featured in peer-reviewed academic studies—protocols used on everyone from cardiac rehabilitation patients to high-caliber athletes. I describe the workouts’ scientifically assessed benefits and finish with some tips to help you design your own. But first, a few words about how we quantify “effort.”

Fast and Furious: Assessing Intensity

Envision a typical spin class. A trainer straddles a bike that faces a dozen clients on exercise bikes. Shouting loud enough to be heard over a pounding techno beat, she barks into her headset: “Give me 90 percent in three . . . two . . . one . . . And go!” All around the room, veterans and first-timers alike mash their pedals. But chances are they’re all working at different rates—because they have different perceptions of what a 90 percent effort feels like.

Which brings us to one of the trickiest elements of high-intensity interval training: How do you convey to someone the effort required for a given sprint? Many different ways exist to measure exercise intensity. But most of them have been designed to work with long-duration continuous aerobic workouts—and, when applied to sprints, each of them comes with its own idiosyncratic problems.

Vo2max and Power

Traditionally, the most precise way to determine workout intensity involves measuring how much oxygen a person uses during exercise. We express that measurement relative to the person’s maximal oxygen uptake, or VO2max. So we might say a person is cycling at 75 percent of their VO2max. However, several problems exist when using VO2max to describe the effort expended in intervals. In a sprint, it’s possible to run many times faster than the pace needed to elicit your VO2max. And measuring VO2max is unwieldy, requiring a mask over the mouth and nose, and breathing tubes leading to a device that measures the difference in the oxygen content of the air the subject inhales and exhales. It’s just not practical outside a lab.

Another scientific measure of exertion is power, which is most commonly measured in watts. The same unit is used to describe the brightness of a lightbulb or the energy efficiency of your fridge. A watt is a measure of the rate that work is done. On a bike, healthy but untrained people might reach their VO2max at a power output of 300 watts—but in a sprint, that same person can generate 900 watts for a few seconds, while elite track cyclists can achieve 2,000 watts or more. That’s a work rate that could light twenty 100-watt bulbs—enough to illuminate an entire large house. The trouble with that measure? We want each of these workouts to be adaptable to many different forms of exercise. While computers can easily measure watts on exercise bikes, it’s hard to determine power output with other activities such as swimming or running.

The Trouble with Heart Rate

Another common way to describe exercise intensity is relative to a person’s maximum heart rate. (A convenient way to estimate this value is 220 minus your age, although a lot of variation exists between individuals.) “Go for a run at 65 percent of your maximum heart rate,” one trainer might say—a rate of exertion that would see a typical forty-year-old aim for an average heart rate of 117 beats per minute. That’s a lot easier to measure outside the lab because heart-rate monitors are getting more portable and accurate all the time.

The trouble is, heart rate is also a problematic measure to describe the intensity of maximal and near-maximal sprints. Because heart rate lags effort, especially at the start of intense exercise. “Go as hard as you would to save your child from an oncoming car,” I tell people when I want them to give me an all-out sprint. But after a thirty-second all-out sprint, your heart rate might get up to only about 70 percent of its maximum. That’s because when you exercise very vigorously, it takes the cardiovascular system a bit to catch up. The only time you reach your maximal heart rate is through hard aerobic exercise sustained over a few minutes, or over the course of repeated sprints with very short recovery periods. So while the percentage of maximum heart rate works well as an indicator of exertion during steady-state aerobic exercise, and it can even be adopted for less-intense sprints, it’s a lot more problematic for describing the exertion required to sprint at an all-out pace.

So What’s the Answer?

The solution begins with something physiologists call rating of perceived exertion, or RPE. The psychologist Gunnar A.V. Borg of the University of Stockholm introduced the concept in 1970. Borg tied his rating of perceived exertion to heart rate. The original scale went from 6 to 20—a range that roughly matched the heart rate of an average young person divided by 10; it began at 6 because an average young person’s heart rate is around 60, and it went up to 20 because that same young person’s heart rate tops out at about 200 beats per minute. Walking, or “light” exercise, would correspond to an RPE of 10 or 11.

A scale from 6 to 20 is a bit unwieldy, so Borg subsequently came up with a simpler RPE range from 1 to 10, with 1 being described as “nothing at all” and 10 as “very, very strong (near max).”

The intensity scale of the workouts described in this book is modeled on Borg’s revised RPE scale. Note that, as with Borg’s scale, it’s possible to go higher than 10 here as well. Looking at the following chart, you’ll see that the “10+” rating indicates an all-out sprint—equal to my old descriptor of “as fast as you would go if you were saving your child from an oncoming car.” To provide a rough guide, the figures below match exertion levels with the proper score on Borg’s revised scale.

Visit bit.ly/2gJzxTM for a larger version of this chart.

What’s with the Ascending Exertion Ratings for Some Workouts?

Because I perform most of my workouts on my home exercise bike—a Life Fitness 95Ci, to be specific—I tend to base my own sprint workouts on absolute workloads, which tie the outputs to a specific workload that I have to maintain. My bike allows me to plug in a certain power setting—say, 250 watts. And then I’ll do five intervals of five minutes apiece with a minute of recovery. My heart rate climbs throughout the five sprints—and I know that last interval is going to be a beast. I like it because the challenge increases over the course of the workout. When I finish, I know I’ve given my all. I’m really spent—and I feel great.

Which brings us to one facet of the workouts you may already have noticed if you skipped ahead. Some of the exertion ratings increase through the course of the workouts. That’s because I’m basing the workouts on protocols featured in the actual scientific studies that established the remarkable potency of high-intensity interval training. Some workouts are based on sprints with near-maximum or maximum efforts. In those cases, the person’s power output or actual speed declines with each successive sprint—because the all-out effort of the previous sprint is tiring and makes less energy available for the next sprint.

However, some of these workouts are based on studies that required the subjects to generate the same power output with each sprint, regardless of whether it was the first or the last rep. These workouts tend to feature sprints that are intense, but something less than all-out. So, for example, in the study that established the potency of the Ten by One protocol, we asked the subjects to pedal at the same power output all the way through the workout. And to do that, they had to work a little harder each time. (The analogy holds for other types of interval training. For example, if you’re a runner, envision being asked to run up the same hill at the same speed ten times in a row—of course, you would have to exert more effort to achieve the same speed through each successive hill run.)

Hence, the increasing exertion rating for the workouts that are intense but not all-out. Because we’re citing studies that scientists conducted with absolute workloads, the exertion level would have increased throughout them. And to be sure you’re getting the same benefits as the study subjects, you should increase your exertion throughout the workout as well.

A Few Quick Words About Calories

Many exercise books note the calories burned in a given workout. So do exercise bikes. The one in my basement even takes into account variables like the workload setting and duration, as well as my weight and age. But the “calories burned” measure is really just an estimate—an average for people like me. It’s not an exact measure because no exercise bike can know every one of the variables that influence the number of calories burned. So many factors influence that statistic, including your own genetic makeup.

Also, we intend these exercises to be templates applicable to just about any aerobic exercise, from cycling and running to repeating burpees and stair climbing. The number of calories burned also changes depending on the type of exercise you’re doing. And finally, there’s the notion of afterburn—a word that trainers often use to describe the increased number of calories your body expends while recovering from the exercise. The more technical term for the phenomenon is “excess post-exercise oxygen consumption,” or “EPOC,” and it is influenced by the intensity of the exercise you’ve just done. The more intense the exercise, the higher the number of calories consumed in the afterburn. (We’ll discuss EPOC and intense exercise more in chapter eight.)

The point is, we can’t provide you with the exact number of calories burned during these workouts because it depends on the actual workload as well as your own physiology. Suffice it to say that when you factor in the afterburn, all the workouts described in this chapter consume more calories than an equivalent period of traditional steady-state exercise. For some of the workouts, we have verified this directly in the lab. For example, the Ten by One elicits an increase in energy expenditure (that is, calories burned over twenty-four hours) that is similar to a bout of moderate-intensity continuous exercise lasting about twice as long.

Modifying Your Interval Workout

The following workouts are only suggestions. Feel free to change them any way you see fit. That’s the beauty of interval workouts. They can be variable to a nearly infinite degree. One thing I’d suggest considering is figuring out a way to get comfortable incorporating some resistance training into your workouts. That’s because resistance training becomes increasingly important the older you get. It’s the sort of exercise that builds strength; it encompasses weightlifting, bodyweight movements like push-ups and pull-ups, kettlebell training, and workouts using the Universal machines you see in fitness centers.

It’s well established that combining aerobic and resistance training reduces body fat better than aerobic exercise alone. The resistance training also combats the muscle-wasting effects of aging. And it makes you look better.

Happily, many interval-training protocols are well suited to incorporate resistance training. Several different approaches exist—and each one tends to be hyperefficient, because it works a lot of different physiological systems in a short amount of time. One involves performing bodyweight exercises during the “rest” portions. So in the four and a half minutes of rest specified between thirty-second sprints in the Wingate Classic, for example, you might perform squats, burpees, push-ups, or pull-ups. The trouble with this approach is that the resistance training tires you out, so you have less energy available to devote to performing your sprints.

The way that I prefer, which also happens to be the way that many personal trainers do things, involves bodyweight exercises, or resistance-training movements in which the body is the “weight” lifted. Whether we’re talking push-ups, pull-ups, burpees, squats, or the dozens of other variations, bodyweight exercises work many different muscle groups, which means they also elevate the heart rate. Performing them quickly exercises the aerobic system—which in turn means that bodyweight exercise can be performed as interval-training sprints.

So to incorporate resistance training into a sprint workout, simply swap out the run, swim, or cycling activity with any bodyweight exercise that elevates the heart rate to a similar extent. The trick is to avoid workouts with long-duration sprints, because few people can perform bodyweight exercises for any significant length of time. I wouldn’t try to adapt the Norwegian workout to a bodyweight approach, for example, because the four-minute-long intervals will be too tough if you do push-ups for your sprint intervals.

Among the protocols in chapters six and seven, the Fat Burner and the Tabata Classic both work well with bodyweight sprints, as does the Ten by One. But feel free to experiment with the protocols and customize them to your particular needs. I have a favorite bodyweight-sprint workout that involves ten minutes’ worth of thirty-second-on, thirty-second-off intervals. The first thirty-second work interval is a warm-up exercise of jumping jacks. The second “on” interval is push-ups. The third is pull-ups from a bar, and the fourth is squats. Then repeat the cycles of push-ups, pull-ups, and squats until you’ve conducted three sets of each, for a total workout duration of ten minutes. It’s fun, and super time-efficient because I’m getting in my daily resistance and aerobic training in less time than it takes to walk the dog.

Team sports are another way to incorporate interval workouts into your fitness routine. My family is crazy about team sports. I play hockey once a week. My wife plays both hockey and soccer, usually on multiple teams a season, and both my sons play competitive hockey. Such experiences have provided me with many opportunities to observe how those playing team sports can incorporate interval-based physical activity without actually performing a specific interval workout.

Think about it: In hockey, on a team with three full lines, a typical shift is thirty to forty-five seconds long. The shift amounts to a sprint—a nearly all-out burst of activity that leaves me huffing for breath, and my heart pounding, fifteen to twenty times a game. Hockey is a great interval workout.

So is soccer, with its breakaways and runs into space; players can jog more than six miles in a professional game. Full-court basketball qualifies as an interval workout, too. As do Ultimate Frisbee and touch football. In fact, many team sports amount to the best kind of sprint sessions. Conducted with friends, at near all-out intensities, they likely provide their participants with plenty of benefits.

But how much? A fellow academic from my hockey group, McMaster’s Peter Kitchen, coauthored a 2016 study that found that male recreational hockey players ages thirty-five and over tend to have lower rates of diabetes, high blood pressure, and heart disease than do other physically active males.

Similarly, a 2010 paper revealed that recreational soccer players took part in intense intervals, with their heart rates averaging higher than 90 percent of their maximum for 20 percent of the game, leading to increases in muscle mass and cardiorespiratory fitness that were greater than those in a comparative group of endurance runners.

The point? If you’re looking for a fun, social alternative to interval workouts that nevertheless provides many of the same benefits, consider playing team sports.

How to Approach the Workouts

All the workouts described in this chapter are based on formats used in actual scientific studies. Some of these studies featured warm-ups and cool-downs that ranged from five to ten minutes long, whereas other studies did not explicitly describe such details. Most people will do fine with a three-minute warm-up and a two-minute cool-down, so in the interests of time-efficiency and consistency, that’s generally what is specified here. As you will see from the descriptions, certain workouts are more suited for certain types of people—whether beginners or those who have progressed further in their training. If you opt to set yourself on a path toward vigorous exercise, here’s how I’d approach things:

Step 1: First, always check with a physician before starting or changing an exercise routine. Once you’ve received the all clear from your doctor . . .

Step 2: If you’re out of shape, don’t try to be a hero. Mitigate the low risk that exists by starting with easy workouts and then working your way up to tougher ones. Don’t begin with all-out sprints. Instead, try an interval-walking program and move gradually to more intense workouts like the Ten by One and the 10-20-30 (both of which you can find in this chapter). We call these intense but submaximal protocols, because while the formats ask the participants to work out hard, the protocols don’t request all-out intensities.

Step 3: Only when you’re comfortable with variations of submaximal interval protocols should you consider moving up to the expert workouts—the bodyweight circuit-training formats like the Tabata Bodyweight or Go-To workouts in chapter seven. Same goes for the really potent, ultratime-efficient all-out workouts such as the One-Minute Workout and the Wingate Classic. I’ll say it again: These are not for beginners—work up to them, and once you’re ready, feel proud that you’re in-shape enough to enjoy the benefits of the most potent, time-efficient exercises available.