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What the Heck is HIIT?

What the Heck is HIIT?

We see a lot of fads come and go in the fitness world, and unfortunately most of them are ultimately a waste of time. However, there’s one recent trend that everyone should add to their arsenal – HIIT.

HIIT stands for High Intensity Interval Training, and it’s performed just as the name suggests. You repeat bouts of high intensity work interspersed with periods of rest. Your heart rate and breathing should rapidly increase from the work, and they should have a chance to recover during the rest. Since the work is so intense, you don’t have to work very long to get the benefits you’re looking for. Some pretty convincing research has been published touting the benefits of HIIT compared to traditional cardio, and you can read more about that here.

Some benefits of HIIT include

  • More efficient use of time in the gym
  • HIIT is more interesting than steady state cardio (aka more fun)
  • The cardiovascular benefits of HIIT are equal to, if not better than, traditional cardio in most cases
  • HIIT can be beneficial for joint health – less repetitive impact on knees, hips, low back
  • HIIT maintains (or many even improve) lean muscle mass and connective tissue integrity


The biggest mistake folks make when trying to follow a HIIT workout is messing up the intensity. High Intensity is obviously a key part of this method. The intensity or effort you put in needs to be maximum or near maximum, which isn’t always a lot of fun (at least not the first time you try it).


How do you gauge your intensity?

We can directly measure intensity by looking at heart rate (HR). Resting HR is typically around 60-70 beats per minute (bpm), and HR increases to about 130-150 bpm during steady state cardio. Performing high intensity intervals should rocket your HR up to 180 bpm or more. You will quickly realize that you can’t keep up this intensity for very long, but that is the point!


Of course measuring your heart rate isn’t always practical, so you can utilize another measurement that’s a bit more subjective – RPE. Your Rating of Perceived Exertion (RPE) is a scale from 1 to 10, 1 being very easy and 10 being max effort, that you can use to judge your intensity. It is up to you to interpret this scale based on your current ability, but the chart below offers some examples. HIIT should take place in the 8-10 range.


Again, reaching this intensity is key to making HIIT work for you. The trade-off for not having to work as long is that you have to work much harder. HIIT sessions can be done with standard cardio movements and equipment (treadmills, bikes), or you can implement different exercises to add some variety – medicine ball slams, burpees, and tuck jumps are always effective.


Some things to consider when following a HIIT program

Make sure the exercises you choose can elevate your HR quickly. If it takes you a minute or two to build up intensity, or if you’re not working enough muscle groups, you will miss out on the benefits.

  • Sprints and burpees will always beat out planks and bicep curls.

Picking the right exercise is the first step, but performing it with max effort is key.

  • You can pick up a medicine ball and drop it to the ground, but that’s not the same thing as slamming it into the ground as hard as you can (make sure you have a ball that won’t bounce back!).

Rest is ultra-important! You have to rest in order to put max effort into the following bouts of work. Rest is not being lazy, it’s being smart.

  • This doesn’t mean jogging at 6mph then resting at 4mph, it means sprinting at 10mph and standing still to rest (or walking very slowly)
  • Rest intervals need to be long enough to allow for max effort on the following bout, so you may rest 5-10 times as long as you worked. If you run an all-out sprint for 10 seconds, it may be necessary to rest for 2 minutes before repeating the sprint. For a longer bout of work, say 30 seconds, you may only need a 1:2 work to rest ratio (rest for 60 seconds).
  • As you progress and decide you need a new challenge, you can even try 2:1 work to rest ratios (e.g. 20s on, 10s off, repeated for 4 minutes is the Tabata method)

If you’re doing it right, you should not be able to perform a HIIT workout for longer than 30 minutes (nor should you want to), and ideally it would take even less time than that. This style of exercise does not need to turn into an hour-long ordeal. It needs to be intense and quick. The intensity should also limit you to only performing 2-3 HIIT workouts per week. Any more than that and you may not give yourself adequate recovery time.

This is an awesome method to add into your routine, and there is no better time than now to give it a shot. You could try putting a couple or workouts together yourself, but some even better options would be taking a Group Fitness class that utilizes HIIT methods, or scheduling an appointment with a Personal Trainer who can customize a program just for you.

Ryan Keller, MS, CSCS, NSCA-CPT
NSCA Texas State Director
Fitness Director
Campus Recreation
Texas Christian University