The Science behind High Intensity Interval Training


I have been hearing a lot about HIIT and weight loss online lately. Although I have taught Tabata style workouts in the past I honest haven't looked into the science behind the workout until now. After digging through a handful of scientific articles I found a lot of interesting benefits of the workout. For starters, you don't need to spend much time in the gym. To be honest I think I had a hard time believing that. Everyone knows that if you spend at least 30-45 mins in the gym to really get results, right?

That is not always the case. High Intensity Interval Training or HIIT has small time requirement and  big benefits. You can do a 14min workout (including warm up, workout, cool down) vs 30min steady state workout and receive an equivalent and/or a superior workout if you are looking for weight loss. According to another study, only three 10 minute sessions a week can begin to show results for endurance training (slow twitch) and cardiovascular and metabolic health. Why should you care? Well, for starters this keeps your heart healthy and who doesn't want that? The exercise is also known for decreasing insulin resistance. In case you didn't know insulin resistance is a precursor for type 2 diabetes.

My background is exercise sports science so if we dive into the biology side of exercise we find the HIIT program promotes the systems in the body that break down fat and sugar which converts it into ATP (energy) and increases the utilization of skeletal muscle oxidizing fat as an energy system. So what does that mean? It essentially means HIIT is a fat burning exercise.


Another way HIIT is a burns fat by releasing a hormone known as epinephrine which is shown to activate lipolysis which releases fat from both subcutaneous, (the jiggly fat right below the skin) and intramuscular fat stores (think chubby muscular).

There are a lot of styles of HIIT. You can do the exercises with body weight, cardiovascular training  (cycling or running), light weight (50% of your max rep) or a combination. Most of the HIIT studies used the wingate as the controlled exercise. Wingate is typically a test performed on a bike which measures your max anaerobic power and capacity.

As many wonderful benefits that HIIT has you should be warned that participants in the HIIT studies reported the exercise style to be less enjoyable and were less likely to stick with the program so make sure that you keep the workouts fun. I think working out with a friend can be a way to make HIIT more enjoyable.

Here is my free sample plan for HIIT:

8 week training period
24 sessions
3 times a week

Start with a 5 min warm up on bike with light resistance
3 Tabatas ( you can easily download a free app on your phone I like the Tabata Timer)

Tabata 1 cardio: bike or treadmill your choice

20 secs on full out sprint: breathing should be difficult, you should feel like dying by round 3

10 sec rest in between each round

8 rounds total

Tabata 2: (alternate between working different muscle groups)

Monday workout-- push ups, use your knees to modify, you don't want to blow out a shoulder so you can always walk your knees in closer to your hands to make the exercise easier. The first 4 rounds are standard wide push ups, the last 4 rounds are tricep push ups


Wednesday workout---squats, you can modify by just working your body weight or begin to add in a light kettlebell or dumbbell


Friday---burpees, to modify by putting your knees down or use a wall ball, you can always make the exercise more challenging by adding an explosive jump at the end. There a thousand different burpee variations be sure to switch it up to keep the workout interesting

Tabata 3: planks: can modify by coming to forearms or even into the knees, make sure you isometrically pull your hands towards your toes and your toes to your hands (think about if you can wrinkle the floor)

20 secs on, by round 3 you should be shaking!

10 sec rest

eight rounds

5min cool down static stretching and foam rolling!

Remember its called HIGH INTENSITY interval training! Every round you need to be giving it your all and really pushing yourself! Good Luck! Let me know if you have any questions and how its going for you!