A Primer On HIIT – High Intensity Interval Training

HIIT, “high intensity interval training”, is a topic many people have questions about, as it provides an interesting alternative to traditional cardio. Here are some pointers on how to utilize this technique.

What Precisely Is “HIIT”?

The generally accepted definition is: performing an exercise at a rate that’s near your maximum exertion for short time intervals, alternated with intervals of slower paced recovery activity, or with rest periods.

An easy way to measure the difference between “near maximum exertion” and “recovery” is to rate your exertion on a scale of 1 to 10, with 1 being “I can do this all day”, to 10 being “OMG I’m going to pass out in 15 seconds”. The high intensity portion of your activity should be around an exertion level of 8 or 9, and the recovery / rest portion should be around 5 or 6.

Just like traditional, steady state cardio, you can do HIIT with any activity that will get your heart rate /exertion level up. Running, swimming, jumping /skipping rope, cycling, elliptical, burpees, digging ditches; if you can do it intensely enough to get to 8 or 9 on the exertion scale, then it will work for HIIT.

Why HIIT?

Basically, what researchers have found is that steady cardio burns the same number or more calories during the activity as HIIT, but HIIT continues to burn more calories even after you’re done. While steady state cardio might burn more fat calories, when it comes to losing weight, it doesn’t matter what kind of calories you burn, only the total number of calories.

Furthermore, HIIT increases fat oxidation (fat burning) in muscle fibers; research showed that people who did HIIT on a regular basis had lower body fat percentages than those who did steady state cardio.

How Long Should A HIIT Session Be?

How much HIIT equals steady state cardio? That’s a bit more difficult to figure out. A recent study had one group do 40 minutes for a total session, alternating one minute of high intensity with one minute of rest; and a second group did 90-120 minutes of steady state cardio.

When the researchers compared results, they found that people who did 80 minutes of high intensity cardio (not including the rest minutes) showed about the same improvements as those who did 825 minutes of steady state cardio.

I doubt this means that you only have to do 10% of the steady state cardio time you have done before! Most of what I read recommended HIIT sessions to be about half the time of your steady state cardio, working up to a HIIT session between 15 and 30 minutes long (depending on your fitness level, goals, and any sport-specific HIIT you’re doing).

Who Should Do HIIT And How?

HIIT is not recommended for novice exercisers. It puts a high demand on your body, and if you’re not used to exercising, you can increase the possibility of injury. If you are a beginner, you can find some tips on learning to run right here.

If you have high blood pressure, heart disease, or joint problems like arthritis, also talk to your doctor before you start with HIIT.

Here are some tips:

• ALWAYS warm up completely before you begin, preferably with the same activity you’re going to do for HIIT. (Walk and run slowly before you begin sprinting; cycle slowly before you start cycling hard, etc.) ALWAYS cool down slowly and stretch when you’re done!

• Be realistic with what you attempt, and keep in mind how you might feel tomorrow. That high intensity exercise you did today might feel okay today, but give you major DOMS tomorrow, and affect your workout plans.

• Start slowly. Alternate two minutes higher intensity with two minutes of lower intensity. Assess how you did, and see how you feel the next day or two.

• Begin by doing HIIT once or twice a week, and gradually work your way up to doing it more often. Keep in mind your goals; if you’re working toward doing a marathon or triathlon, you still need to do longer steady state cardio tailored to those sports.

• Be careful about overtraining. You can overtrain with HIIT just as you can with any other exercise activity. If you feel like you’re not improving, or your performance is going backwards, you just feel generally ‘tired’, or you have continuing aches and pains, then ease off on how often you do HIIT.

• To get better, increase intensity OR duration, but not both at the same time!

What’s A Good HIIT Routine?

Again, if you’re just starting doing any sort of cardio, don’t attempt HIIT yet. Ease into cardio and work up, so you can do your cardio of choice for 30 minutes. If, after that, you decide to go on a HIIT routine, it’s best to go with 2 minutes of high intensity, alternated with 2 minutes of recovery (lower intensity or rest), for 10-20 minutes total.

Below is an example routine. Before trying it out, please remember to properly warm up and stretch afterwards:

• Run fast 2 minutes
• Run slow or walk 2 minutes
• Repeat until you reach 10-20 minutes total

When you get used to doing HIIT, you reduce the intervals to 1 minute each. If you prefer to do this on a bike, you just replace the “run” with “bike”.

HIIT is also a favorite of many cyclists

An alternative many people enjoy is called “pyramids”, a training structure where the intensity reaches a peak and then goes in reverse. Here is an example:

• Cardio fast 1 minute
• Cardio slow 2 minutes
• Cardio fast 1 minute
• Cardio slow 1 minute 30 seconds
• Cardio fast 1 minute
• Cardio slow 1 minute
• Cardio fast 1 minute
• Cardio slow 30 seconds
• Cardio fast 1 minute
• Cardio slow 1 minute
• Cardio fast 1 minute
• Cardio slow 1 minute 30 seconds
• Cardio fast 1 minute
• Cardio slow 2 minutes
• Cardio fast 1 minute

In place of distance you can also use time; instead of 1 minute, do 200 meters (or 300 meters, or “from here to that house and back again”).

It’s No Rocket Science

As you see, you don’t need an “expert” to make up a HIIT routine for you. Take your favorite cardio activity (or the cardio you hate the least…) and alternate the intensity every one or two minutes. You can even mix up the type of cardio activity; do one interval of burpees, recovery interval, one interval of jumping rope, recovery interval, one interval of sprinting, recovery interval.. and so on. As long as that intense interval is at an 8 or 9 exertion level, and the recovery interval is around 5 or 6, it will work!

This article was written by Goldie, who actually is an expert in martial arts, cardio activities and strength training.

Pictures courtesy of “lululemon“.