The SCIENCE of High Intensity Interval Training

 

|By Nadine Shaban|

Fact: Obesity has officially become an epidemic and the number of people being classified as obese is growing (probably exponentially) every day. In fact, the prevalence of diabetes follows obesity by about 10 years. Although the prevalence of diabetes is growing in our society, it is not a new disorder. Diabetes Mellitus (DM) and Obesity have become a global epidemic…hence for the new disorder: DIABESITY.

Fact: Being female has its perks, however, when it comes to NON estrogen related issues, we need to take care of ourselves. Women are more likely to have Cardiovascular Disease (CVD)…the NUMBER ONE cause of DEATH globally. Women with diabetes have a greater risk for developing CVD.

Fact: The increase in diabetes diagnoses has already exceeded the 65% Canadian increase that was predicted to occur within 35 years from 1995 to 2030.

Seriously…this is for real. And the best part is there’s no need for long duration steady state cardio.

So, do you still want to grab that Krispy Kreme donut? Is the drive through still calling your name? Unless the drive through has you doing some type of metabolic workout, I hope not.

I think I may have a solution for you. While it may not taste as good as that fat laden and sugar filled meal, it can help you lose body fat, and continue to burn fat for hours after you train in less than 30 minutes.

Seriously…this is for real. And the best part is there’s no need for long duration steady state cardio.

Enter the world of high-intensity interval training.

Coach G takes WBFF Bikini Pro Kelly Boone through a High Intensity SHOCK Trainingworkout. Randi Lotsberg Photography

Interval training is a time-efficient form of exercise that generates similar benefits to long duration, steady state exercise.  Several studies (e.g. Burgomaster et al (2005, 2006) have consistently shown that 4-6 sessions of 30-second all out sprints, followed by 4 minutes of recovery (i.e. rest or low intensity exercise) after each sprint is a time efficient protocol for improving many of the fitness parameters normally associated with aerobic exercise (e.g. increased GLUT-4 and muscle metabolic enzymes). These physical and metabolic adaptations can reduce the risk of many chronic diseases and illnesses such as obesity and Type 2 diabetes (T2D).

HIIT is a time efficient training method for athletes trying to get lean that can also improve many markers associated with obesity and diabetes.

What is more remarkable is that these physiological benefits are seen in high intensity interval training (HIIT) which is typically 90 and 70% lower in exercise volume and time spent training, respectively, compared to endurance training. Therefore, HIIT is a time efficient training method for athletes trying to get lean that can also improve many markers associated with obesity and diabetes.

WARNING: the next section is for the geeks… physiology 101 – Nadine style.

In order to understand the differences and/or similarities between interval training and endurance training it is first important to properly distinguish between the anaerobic and aerobic system. The anaerobic system is defined as the ability to produce energy in absence of oxygen. This energy is known in the scientific community as adenosine triphosphate (ATP), which is a high-energy phosphate compound that when hydrolyzed (broken down ATP – ADP + Pi) releases energy. The phosphagen system and Glycolysis are two common anaerobic systems that generate ATP or energy for use in high intensity, short duration exercise.  In contrast, the aerobic system is the ability to produce energy in the presence of oxygen, and is therefore, dependent upon the availability of oxygen.  The Tricarboxylic Acid Cycle and the Electron Transport Chain are the systems that synthesize ATP this way and are vital to activity that can be maintained for long duration.

Are you with me still or did I just bore you and remind you of what class was like when you were taking Physiology 101? Oh wait, you were probably sleeping just as you are now, so wake up and let’s put this science stuff to use.

Here’s a familiar scenario to many of us: you wake up for school/work and realize you are running late… as you go outside your bus just passes by (oh boy… gotta run for it). You start sprinting as fast as you can. During that first 10sec sprint, you are using your phosphocreatine system. 10 seconds have passed and you continue sprinting because you have yet to reach that bus. At this stage, your phosphocreatine levels start to run low, and glycolysis kicks in. As you continue you will slowly start to slow down and you will start producing a substrate known as lactic acid aka, “the devil”.

Figure 1: A snapshot of the energy systems involved in High Intensity Interval Training.

It is important to note that no energy system is more important than the other. Each energy system functions together and each system is never shut off or ceases to contribute to the production of ATP. Depending on the nature of the task, and the demands of the body, one system may work or contribute more than the other. As seen in Figure 1, energy contribution is a continuum, where there is a general transition from one energy source to another depending on the intensity and time of the exercise.

To summarize:

A marathon event or any type of activity that requires you to work at a LOW intensity, and for a longer duration utilizes the aerobic energy systems as it requires oxygen. We are using oxygen to have energy through the breakdown of carbohydrates and fats.

On the contrary, when you are sprinting, or doing high intensity exercise, you are utilizing your anaerobic metabolism. You are not using oxygen and that is why you are not able to sustain your power and energy for a long period of time.

Easy peezy right? if only you had me when you were taking good old Physiology 101.

So what does this have to do with HIIT?

With HITT, you are alternating between the two energy systems. Typically you would go hard for a short period of high intensity exercise followed by a recovery period of lower intensity. The high intensity is where all the work is done and where if performed correctly, all of the “benefits” are made, while the lower intensity is there to stimulate recovery and have you catch your breath.

The high intensity is where all the work is done and where if performed correctly, all of the “benefits” are made, while the lower intensity is there to stimulate recovery and have you catch your breath.

END OF GEEK SESSION.

The question you are probably asking…aside from getting  in a good workout in the amount of time it takes to wash your car or do your nails (ladies), what other physiological benefits are there?

• Increased Metabolic Enzymes
• Increased Resting Muscle Glycogen
• Increased GLUT4 Content
• High intensity resistance training will elicit a greater post-exercise oxygen response than lower intensity resistance training.
• Increased activity of the heart and respiratory muscles
• Elevated levels of hormones and enzymes that increase metabolic activity
• Greater reduction in subcutaneous fat (fat under the skin)
• Increased EPOC- raised metabolism for 3 hours after the session.

High intensity Interval Training can be done anywhere and with minimal equipment.Randi Lotsberg Photography

Interval training can be done anywhere and using any type of equipment and machinery. Therefore, the excuse that “I don’t have access to a treadmill, bike, etc…” doesn’t work – we all have access to pavement. That’s right, going outside and sprinting! Many of the studies used mathematical formulas and really pushed the athletes to their maximum. Fancy math skills are not required; just make sure you are going as hard as you can.

Interval training can be done anywhere and using any type of equipment and machinery.

As I have my Precision Nutrition certification in nutrition, I am able to read many of their latest blogs and articles. Dr. Berardi and his colleagues have come up with a wide variety of interval training techniques and methods that are not only fun, but will result in you getting lean fast. Remember, now that we have ONE exercise component down pat, it’s time to get strength training and more importantly nutrition in line as well.

In the next article, I will take you through my own variations of interval training…so get practicing. Get off the computer and get jump squatting. Happy interval training.

Nadine Shaban

Nadine is a talented fitness model, trainer and nutrition expert who also holds a Masters Degree in Exercise Physiology from the University of Windsor. Her research specialty is glucose handling in Type 2 diabetics during high intensity interval exercise (HITT). Nadine also holds a B.S. in Kinesiology from the University of Windsor. In addition, Nadine is a certified strength coach under Charles Poliquin, a certified Biosignature Practitioner through Charles Poliquin, and a certified nutritional consultant through Precision Nutrition.

Nadine’s personal philosophy is to challenge people beyond what they believe they are capable of accomplishing. She hopes to inspire people to adapt to a healthier lifestyle. She believes people not only need to change their mindset towards exercise, but must also have a positive and balanced relationship with food. She truly believes a healthy mind represents a healthy body. For nutrition consultation or personal training, you can contact Nadine at nadineshaban@gmail.com.