High Intensity Interval Training or HIIT Training – What Is it and Why it Works

What is HIIT? (High Intensity Interval Training)

Even though traditional low pace aerobic/ cardio training works effectively in the reduction of stored body fat, this type of training is sadly counter-productive for testosterone production and for muscle preservation.

It is not amusing to spend hours on the treadmill, stationary bike, or stair master, and it is definitely not the best way to lose fat and achieve muscle definition.

However, luckily we have HIIT (High Intensity Interval Training), a method that drastically shortens the length of workouts, increases the total number of calories consumed, improves endurance, accelerates metabolism, and most importantly preserves muscle mass.

As the name suggests, HIIT/ High Intensity Interval Training is a high-intensity interval training method, which consists of short period anaerobic exercises and short breaks in between (1).

The HIIT method is simply a form of cardiovascular exercise during which short-term high intensity intervals (e.g. sprints) can be combined with low intensity/ active recovery intervals (e.g. walking), or with full recovery intervals (2).


Replace an hour of low intensity (long, boring and ineffective cardio training) with 4-30 minutes of fast, effective, interesting and simple HIIT training!

The HIIT method has been proven to increase physical fitness (endurance, strength, speed), sports performance and fitness, which explains why many professional athletes use this type of training. Because of its oxygen consumption effects, HIIT is very effective in burning calories even hours after a given session. Normal aerobic sessions also only raise metabolism by 5-10% after 24 hours, while HIIT boosts metabolism (afterburn effect) for days after the workout (3).

HIIT has numerous benefits, here are just some of them:

  • This form of training positively affects cardiovascular health, improves anaerobic capacity and aerobic endurance, as well as strength (opposed to traditional aerobic training that only improves aerobic endurance);

  • It enhances growth hormone production that contributes to the “fat burning” effect while simultaneously preserving the hard-earned muscle mass;

  • It increases insulin sensitivity which helps in the prevention of Type 2 diabetes, and it also regulates insulin secretion that prevents overeating and promotes weight loss;

  • Since HIIT workouts are much shorter than regular cardio they create habits and continuity faster;

  • HIIT develops inner willpower to perform intense training, or to increase tolerance to physical pain, which is essential for resistance training.


HIIT training can be performed anywhere (indoor or outdoor, in the park etc.) and with equipment (stepper, stationary bike, running belt, rowing ergometer, box bag, kettlebells, etc.) or without it.


You can incorporate HIIT as a separate training regime, or you use it after your usual training in the gym or at home.


If you use HIIT as a separate regime, a proper warmup routine is essential.

Start of slow and then accelerate to about 90% of your maximum heart rate (220 – the number of years) and hold that intensity for 15 to 30 seconds (intervals longer than 30 seconds will result in even more lost calories) and slow down for 1 minute of low intensity. Repeat the process, maximize intensity for 15 to 30 seconds and then slow down.

So at high intensity intervals the goal is to give your maximum, and at low intensity/ recovery intervals, to decrease the heart rate to about 50% of the maximum.

Also, longer low intensity/ recovery intervals reduce the risk of overtraining, so you might want to consider taking longer rest intervals. This will allow you to perform HIIT workouts more frequently, while also preventing muscle loss and immune function problems.

How much:

HIIT training can last anywhere from 4-30 minutes, depending on your level of physical capabilities. For beginners, a 5-10 minute workout is enough.

HIIT Examples

There are plenty of exercises which can be incorporated in to your HIIT training. These include either various exercises with your own bodyweight (running, jumping, marines, jump squats, jumping jacks, high jumps, etc.), or with some form of accessories.

Here are just some of the exercises you can try with HIIT:

  • Sprints / 35-45 m, pause 1 min. x 10-15 sets; Run up a flight of stairs/ sprint 40 steps up, pause / walk down or run slightly x 10-15 sets;

  • Rope jumping / 1 min. / pause 30 sec. x 10-15 sets;

  • Stationary biker or any other cardio machine / maximum speed for 1 min. / pause 30 sec. or reduce speed x 10 to 15 sets;

  • Tabata variation / Jumping Jacks 20 sec. + low jumps 10 sec. x 8 sets; 4 mountain climbers + 1 marine jump, maximum intensity for 20 sec. with 10 sec. of rest x 8 sets;

  • Bodyweight leg exercises /

  1. 20 fast squats + 10 back lunges + 10 step ups + 10 jump squats / 1 min. x 3 sets

  2. 20 fast squats + 20 sec. static squat + 10 marine squats + 10 jump squats / 1min. x 3 sets

  3. Sprint 50 m + jump squats + marine squats / 3 sets with 21, 15, 9 reps each

Important Facts to Keep in Mind

  • Do not forget that HIIT is a very demanding training method that cannot be carried on day to day basis. Recommend to rest for 48-72hrs.

  • It is advised to not run HIIT more than three times a week in order to prevent the risk of overtraining, especially if you are performing HIIT after you regular workout. If you experience any form of tiredness you should scale-down the workout intensity and frequency.

  • It is crucial to drink enough water during and after a HIIT workout.

  • To avoid potential injuries do not forget for warm up properly before each workout session.

  • Individuals who are very obese and those with respiratory, cardiovascular and similar problems should avoid HIIT training.

  • Beginners should not start with high intensity right away, it is recommended they first start with relatively lower to intermediate tempos. HIIT is an advanced training technique…

  • HIIT definitely works, however you won’t experience amazing results right away. Be patient, and you will definitely feel the HIIT benefits.

If you would like us to design or create a HIIT workout for you click here


  1. https://www.ncbi.nlm.nih.gov/pubmed/29683919

  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5790162/

  3. https://www.ncbi.nlm.nih.gov/pubmed/17101527

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