High Intensity Interval Training (HIIT)

High Intensity Interval Training (HIIT)

Man about to take off on a sprint

“HIIT”, or High Intensity Interval Training, is one of the biggest trends in fitness at the moment. Those four little letters have been gracing the pages of fitness magazines and social media accounts for years now, but only in the past couple of years gained a good amount of traction.

The American College of Sports Medicine recently conducted a poll which found HIIT is considered one of the top 5 cardio workouts used in the United States today. What is it though? What distinguishes it from other types of exercise? Isn’t HIIT just more intense cardio?

Thousands of people are converting their traditional 30 minutes treadmill sessions into shorter HIIT sessions every month, so it must be effective. After all, very profitable brands have been built heavily around the concept of HIIT (*cough* Crossfit *cough*).

Does it work?

High intensity interval training consists of short bursts of very strenuous effort, followed by a period of rest. These slower, less intense periods can either be completely still moments or an active recovery time, consisting of lower intensity movements. Rest intervals are meant to help you catch your breath, reduce your heartbeat, and relax a bit before the next period of intense activity. You shouldn’t be able to sustain the high intensity periods for more than a minute or two without stopping!

Conventional long distance runs burn a ton of calories *during the run* and not many afterwards. Research has proven that shorter, more intense workouts burn more calories throughout the day. That research points to why many people have been choosing these types of workouts over traditional, long distance cardio. As added benefits, HIIT can increase your metabolism, potentially improve insulin resistance, and improve heart function. Additionally, although there are periods of rest, these types of workouts have been proven to help individuals increase their overall endurance more quickly than standard steady state cardio.

HIIT sessions can be designed to meet any intensity or fitness level. Considering that you are working to the peak of what your body is capable of, flexibility in how it is conducted is huge; and these workouts are amazingly tailor-able to each individual’s level of fitness.

Why is it so effective?

HIIT is able to burn so many more calories than traditional cardio because of the after burn effect that it creates. This effect is caused by the fluctuation between an aerobic and anaerobic state each participant encounters. These fluctuating patterns of intensity throw your body into a state of confusion, causing it to react in ways that other forms of fitness cannot.

The words “Aerobic” and “Anaerobic” may sound complicated, but they are relatively simple to understand:

  • Aerobic means “with oxygen”.
  • Anaerobic means “without oxygen”
Anaerobic vs Aerobic
Image from ISSA

Aerobic exercise is what Richard Simmons used to do. It consists of things like going for a thirty minute jog, swimming, hiking, and biking. Things that you might start to sweat and breath faster during, but you are still doing OK. Your body takes in more oxygen as you start breathing heavier and pumps it to your heart and muscles. The extra oxygen being taken in allows you to keep up what you are doing for an extended period of time.

Anaerobic exercise, on the other hand, happens when you’re working harder than what your body’s oxygen supply can sustain. Cells
must use their energy stores for fuel when they are not being supplied with oxygen. Using the energy stored in your muscles causes you to keep burning calories long after your workout, since that energy needs to be replenished, muscles need to be rebuilt, etc.

Alternating Push/Pull Cycles

In HIIT, the interwoven periods of rest and high intensity pull you in and out of the aerobic and anaerobic states. Thanks to that alternating pattern, you get a double benefit when you do a HIIT session; the at the moment, higher calorie burning of aerobic exercise and longer duration calorie usage brought along because of anaerobic activity. Your body sustains higher overall metabolic rates during the workout, and keeps burning calories as if you were in an extended rest period throughout the day. Active calorie burning from a HIIT session can last up to 72 hours after a single workout. You could experience around 70 more hours of active calorie burning compared to a typical 30 minute cardio session!

Who is it good for?

People with injuries, lack of time, or even those severely out of shape can benefit from this type of training. HIIT can be customized to basically everyone; barring those with medical issues or doctors orders.

Injuries

Anyone that has joint issues or past injuries knows that the constant pounding on the body from high impact cardio hurts. If you are trying to limit the impact on your joints but want to work out anyways, look for low impact exercises. Utilize exercises such as battle ropes and medicine ball throws, for example. Rowing at faster rates or with higher levels of resistance is another good way to get some HIIT in without killing your joints.

Battle ropes

Healthy athletes and athletes coming back from injury alike use these types of workouts in many division 1 athletic programs. On top of being an excellent routine, it allows people to gain back to where they may have been before the injury. Best of all, they can do so while allowing their injuries to continue to heal. That all depends on the injury of course! This isn’t to say that HIIT has to be a gentler workout. Based on the exercises you choose, you could make it as physically demanding as you want.

Time Constraints

Anyone without a lot of time to workout will appreciate HIIT. Most Tabata workouts, for example, last 4 minutes. Such short (and effective!) workouts remove the ‘no time for exercise’ excuse from pretty much everyone, if you ask me. Great choice for people on vacation who want to continue to exercise without cutting into relaxation time, busy parents shuffling kids around, or those cooped up in an office looking for something quick on their lunch break.

In reality, HIIT is great for anyone looking to quickly increase their overall fitness levels, increase total calories burned, and build up endurance; as well as those who just suffer from old injuries or a lack of time. In short, anyone can benefit from these types of workouts.

How?

If you don’t know where to start, there are hundreds of HIIT workouts available online for free. You can take any pre-made routine and use it as is. Like everything on that routine except burpees (because, who really likes them, change them out for something else.

Starting off can be a bit difficult if you don’t know how hard to go. Depending on your fitness level, you can start with a thirty seconds active – thirty seconds rest tempo. If you find that 30/30 is too hard, modify the tempo to thirty seconds on and one minute off. The longer the rest period is compared to the active period, the easier the workout will be.

Build Your Own

There are really no rules as to what exercises you need to be doing here. That’s part of the beauty of HIIT. Select a few exercises that are going to target a couple different muscle groups to get a total body workout. Mix exercises like jump lunges that target your quads and hamstrings with shoulder taps to target shoulders to work on a few major areas at once! If you are feeling adventurous, maybe you want to do something crazy like 8 minutes of 10 burpees on the minute. The faster you get those 10 burpees done, the longer rest period you have.

If you really want to challenge yourself, mix in some low intensity exercises to your rest periods. Exercises like planks or wall sits during the rest can still allow your heart rate to settle while keeping your muscles contracted.

Woman stretching
Always do a good warmup and stretch before HIIT!

Try this sample workout and tell me you don’t feel good afterwards. Remember to always get a good stretch and a warm up in beforehand. Stretching helps make sure your muscles are ready to go and reduces the likelihood of injury!

  • 30 mountain climbers
  • 20 air squats
  • 10 burpees
  • 1 minute of rest
  • Repeat x 10

HIIT Can Be Fun

High intensity interval training can be incredibly fun and rewarding. The shorter duration’s and more intense workouts can put you in a state of euphoria afterwards. Maybe HIIT can be a new way for you to change up the cardio you are already doing during your everyday routine. After all, since anyone can do it and it doesn’t need much equipment (if any),
it’s good for an on-the-fly workout.

Whether you’re travelling or home with the kids this may just be your new favorite workout.

Don’t forget that to replenish all those energy stores you worked off. Check this helpful guide for help hitting your nutrition goals.