8 Reasons To Try High Intensity Interval Training (HIIT)

There are so many different types of effective workouts out there, and sometimes it’s hard to choose the type of workout that suit our bodies best.

I’ve personally tried numerous different workouts and about 2 years ago, I stumbled upon high intensity interval training — or HIIT for short. Two years ago, I had the absolute worst cardio endurance. I couldn’t even run for 1 minute straight without stopping. I decided to try a HIIT workout and ever since, I fell in love with how quick my endurance began to improve after incorporating HIIT into my weekly workout regime.

Two years later, I’m more toned with less % body fat and with a much higher level of cardio fitness. I decided to do some research on HIIT and its effects on the human body (which is so fascinating to me especially since I’m pursuing a degree in Exercise Science!). So, if you’re wondering if HIIT is the type of workout for you, keep reading!

So, what is HIIT?

HIIT is versatile method of training which alternates maximal effort with resting intervals and improves fitness.

man and woman running on bridge

HIIT consists of 2 phases that repeat for a certain duration of time:

  1. Work interval – time for the actual workout portion (for example, running, swimming, etc).
  2. Rest interval – time for resting between the work intervals. You can either completely stop the workout or do a less intense move.

HIIT involves repeated bouts of high intensity efforts (the work interval) ranging from 5 seconds to 8 minutes followed by recovery periods of either less intense moves or complete rest (rest interval) of varying lengths of time (American College of Sports Medicine 2014).

This is unlike “steady state” exercising which involves running at a steady pace for an extended period of time (such as running on a treadmill for an hour at the same pace).

I personally usually choose running as my preferred form of HIIT. I’ll run on the treadmill at my max speed for 30 seconds (this is my work interval), then step to the sides of the treadmill to rest for another 30 seconds (this is my rest interval). Then, I’ll get back on the treadmill and run again at max speed..and so on! I’ll alternate these work and rest intervals for the duration of 15 to 20 minutes!

Basically, you can choose any form of HIIT (such as running, swimming, biking, etc). So you would run for a certain amount of time, then rest or walk for a certain amount of time, then repeat.

Below are 8 reasons why you should incorporate HIIT in your routine:


1. You can CHOOSE the type of HIIT workout you want to do.

woman biking on trail

Depending on your interests, you can actually choose what time of workout you want to do with HIIT. You can run, bike, swim– anything that involves cardio. This is great because you can change up the type of your HIIT workout on a week to week basis. It never gets boring!

2. NO equipment necessary!

woman running shoes trail

You don’t need to have access to a gym or a pool to do this! You can go outside and run for your work intervals, and walk for your rest intervals.


3. Don’t do this everyday! Just add this to your current workout regime.

For maximal health benefits, you actually shouldn’t do HIIT more than 4x a week because your body needs time to recover! Keeping your workout regime the same and just adding HIIT into your routine can save time and improve your cardio fitness a lot quicker. It’s good to mix up your steady state workouts with HIIT workouts to give your muscles that variety.

I personally like to do HIIT twice a week.  For the rest of the week, I just perform my regular strength and endurance workouts.


4. You can choose your frequency, intensity and duration of work & recovery intervals.

girl working out running up stairs HIIT

As I stated earlier, you can choose your work and rest intervals. I personally have a work interval of 30 seconds and a rest interval of 30 seconds. As long as you follow these 2 guidelines, you can choose whichever frequency, intensity, and duration of your work and rest intervals you want to do:

  1. Your high intensity work interval should be at least 80% of your max heart rate. So, you must work so hard that it would be difficult to carry a conversation with someone.
  2. Your recovery interval should be 40-50% of max heart rate or going at a pace where exercise is easy & comfortable to do while you recover until next work interval. You’d be able to easily carry a conversation with someone.

You can tailor your own HIIT session to your current fitness level, and make appropriate adjustments as your body gets more fit!


5. Cardiovascular improvements from HIIT have proven to result in greater improvements than steady state exercising.

HIIT is better that steady state exercising for improving VO2 max (Journal of Sports Science and Medicine, 2012). VO2 max is the rate at which your body consumes oxygen. The higher the number, the more oxygen your body is using which means that your body is consuming oxygen efficiently. This means there is less stress on your body to get oxygen to your working muscles! An improvement in your VO2 max is a great indicator of an improved level of fitness.

A 2008 study involved measuring VO2 max between men and women who took part in an 8 week HIIT program & continuous steady state endurance training program.

Results: VO2 max increased by 15% with the HIIT program and only 9% in the steady state training program.

HIIT VO2 Max chart


6. HIIT maximizes fat loss. 

healthy apple weights measuring tape

Metabolic improvements with HIIT have shown to be better than that of steady state exercising. According to a 2008 study, over a 15 week period, women who did a HIIT workout for 20 minutes on an exercise bike lost an average of 5.5 pounds more fat than women who just did a steady state workout for 40 minutes.  So, the women who did the HIIT workout lost more fat than in less time than those who did a steady state workout!

Also, after an HIIT session, you are still burning calories because your oxygen consumption remains elevated as your muscle cells try to return your physiological and metabolic mechanisms to normal resting levels. This allows you to burn more calories for a longer period of time after your workout even though you’ve already stopped exercising!


7. HIIT is time efficient!

HIIT sessions only last 20-60 minutes (ACSM) depending on your preferred work & rest intervals. So, if you’re low on time and still want to get a workout in, consider substituting your steady state workout with an HIIT workout! On average, steady state exercising lasts for an hour while HIIT can last as little as 20 minutes according to the American College of Sports Medicine! I personally usually do HIIT for 15 minutes and find it to be just as effective!

Since the health benefits of HIIT are the same, if not better, than that of steady state exercising, feel free to just swap in some HIIT instead of your regular hour-long run. You’ll gain just the same benefits and burn more calories in less time!


8. HIIT results in numerous evident health benefits!

woman raising hands on beach

These benefits include improvements in cardiovascular health, blood pressure, insulin sensitivity, cholesterol, maintaining muscle mass while shedding fat and overall aerobic & anaerobic fitness!

As always, before you begin any workout regime, it is crucial that you get medically cleared by a doctor just as a safety precaution.

If you’re still a bit skeptical about HIIT, give it a try! HIIT is super accessible and time efficient which is great for my busy lifestyle. If you’re also a busy body, try it out! You’ll be impressed by how awesome your body feels after a few weeks of incorporating HIIT into your workout regime.

If you love it, let me know and be sure to share this with your friends so that they can get fit too!