The Original HIIT Protocol
High intensity interval training, more commonly known as HIIT, is now widely known in the world of fitness and accepted as a valid training method to increase aerobic and anaerobic fitness. What you may not know is that a Japanese scientist named Izumi Tabata is one of the driving forces behind this method. Here is the original study if you want all the details.
In 1996 Tabata completed a study to test his new method. He compared a group of men working at a low intensity, 70% of their VO2 max (maximum oxygen consumption, a measure of cardiovascular fitness) for 60 minutes, to a group working at high intensity, 170% of their VO2 max for brief intervals, interspersed with very short periods of rest. The subjects in the high intensity performed 20 seconds of work, followed by a 10 second rest period. This interval was repeated for 8 times, for a grand total of 4 minutes of work. He found that the Tabata protocol was just as good as the traditional low intensity workout for improving aerobic fitness, and a whopping 28% better at improving anaerobic fitness. Since then numerous other studies have conducted similar experiments with similar results. To put it simply, the Tabata protocol works better than traditional cardio to improve fitness, but there’s a catch: It’s really, terribly, brutally hard.
Aerobic Vs. Anaerobic
When most people think of cardio, they picture a runner or a biker, going for a long distance and a long time. These long distance workouts rely on aerobic metabolism, which means oxygen must be present in the muscle cells to produce energy to keep you moving. Aerobic metabolism is great for burning fat, since fat is the primary substrate the cells consume for energy. This is why you see the ‘fat burning zone’ on almost every treadmill and elliptical you see in your gym. While this is a true statement, you body’s energy metabolism isn’t so cut and dry. Your muscles also use glucose, which is primarily stored in the liver and your muscles. Creatine phosphate, which is also stored within the muscle, is another substrate. Your body can also break down protein for energy, but that’s usually a last resort and as such won’t be a part of our discussion.
Whenever you exercise, you’re using a combination of fat, glucose and creatine to fuel your movement, regardless of what you’re doing. Working at a low intensity, like 70% of your VO2 max, allows your body to work comfortably in the aerobic zone. Oxygen is available to the cell so it can freely use that oxygen to burn fat. Here’s the catch though, fat can only be used as energy when oxygen is present. This explains why you can pursue a low intensity activity for hours without severe fatigue. Let’s use walking as an example. You could get up from your desk right now and walk at a comfortable pace for an hour and barely feel the effects. In fact, you could walk for hours on end at that same comfortable pace, and you’ll be using fat as the main source of energy the whole time. Even the skinniest amongst us have enough fat stored for days worth of energy.
Anaerobic metabolism is basically the opposite of aerobic, which means you’re creating energy without oxygen present. Anaerobic metabolism is great for high intensity activities like sprinting, or heavy resistance training. The catch here is that you can only do it for a short period of time before you have to rest or lower the intensity. Imagine you were told to sprint as hard as you could for as long as you could. Your body can on go ‘all out’ for roughly 10 seconds. This doesn’t mean you will stop after 10 seconds, it just means you won’t be able to sustain maximum energy output. Even though it might feel like you’re going as hard as possible, your speed an power will decrease after this time frame. The 100 meter sprint is a classic example of anaerobic metabolism. For elite sprinters, this is a roughly 10 second period where they are running as hard and fast as humanly possible.
Intensity and duration have an inverse relationship. The lower the intensity, the longer you can sustain the exercise. The higher the intensity, the shorter time you can last before stopping or reducing the intensity. Therein lies the beauty of the Tabata protocol, it forces you to work in the anaerobic zone, while giving you just enough rest to repeat it a few times, thereby increasing your ability to tolerate high intensity activity. This is why the Tabata protocol is so effective at increasing your body’s ability to work both aerobic and anaerobically, leading to better results than traditional cardio.
How To Use The Tabata Protocol
First of all, using this protocol requires a commitment. Each 20 second interval requires every ounce of energy to get the best training effect. When your 4 minutes are up your muscles should be burning, lungs gasping for breath and you whispering a prayer of thanks to your deity of choice. It is not for the faint of heart, you have been warned.
There are no shortage of Tabata apps available to keep the time for you, so download one to start. You’ll want the timing to be automated, because when the fatigue sets in, it’s hard to maintain the discipline to start each interval on time. As for exercises selection, you have many options. Want to fry your legs? Do air squats the whole time. I recommend doing just air squats with no external weight the first time, on paper this might seem easy, you will think differently afterward though. Need an upper body pump? Do push-ups, again just regular bodyweight will be more than enough. Really want to get sadistic? Go for burpees, I’m talking real burpees with a push-up and jump. My personal record is 62 burpees in one session. Bodyweight exercises in general are a great way to start since they require no equipment and can be done nearly anywhere. You could also do more traditional cardio exercises like running, rowing, or jump rope.
Like most worthwhile things in life, you get out of it what you put in, and Tabata is no different. Doing a Tabata sucks, there is no way around it, you have to learn to embrace the suck and power through. If you’re the type of person who wants maximum results with the least amount of time, or you just love pushing yourself physically, this is for you. After you’ve finished you can walk by all the people slogging away on the treadmills with the satisfaction of knowing you’re getting better results in a fraction of the time.