What is HIIE?
High intensity intermittent exercise consists of very short exercise intervals dispersed between long rest periods. Exercise which required 100% effort (very fatiguing) and gets the heart rate up over a short duration can be considered HIIE. It has been found that anywhere from 6 seconds + of high intensity exercise is associated with positive benefits.
For example after 10 burpees completed within 30 seconds, you will feel fatigued, be puffing and your heart rate is going crazy! Also, a 10 second sprint leaves you feeling destroyed! A short 10 seconds later you feel fabulous and for unknown reasons maybe want to put yourself through another set!
Why is HIIE so good?
HIIE will leave you feeling refreshed, energised and more alert immediately. In the long term you will increase your aerobic and anaerobic fitness as well as ward off chronic diseases. Your daily exercise routine can be reduced in time, without losing any results. In actual fact, you may see increased results from your workouts. Increasing your energy levels has such positive influences on the way you tackle your daily work, including efficiency and focus of attention. As I willingly say throughout my blog posts – you will be able to achieve more by doing less!
How does high intensity intermittent exercise benefit time efficiency, health, energy levels and productivity?
The underlying processes by which you gain so many benefits from HIIE is rather complex. To put it simply, a series of hormonal responses to the HIIE exercise affect the way your body uses energy (energy metabolism) and how your brain is stimulated (neural stimulation). Here I will focus on changes you will be able to notice and why they occur.
Higher and more steady energy levels
Hormones including catecholamines, cortisol and growth hormones are all increased in your blood as a response to high intensity intermittent exercise. These hormones act on the chemical process which occur in your muscles to metabolise energy stores and create ATP (energy to make your muscles contract).your energy levels and the efficiency at which your body works are increased.
Insulin resistance is decreased meaning your body will process the energy you eat better. When you have decreased insulin resistance, your body maintains a more steady blood glucose level which impacts directly on your energy levels. With big waves of high to low blood glucose levels comes big waves of high to low energy levels. In a low, you feel like you cannot get off the couch and in a high you can’t stand still! Steady energy levels are so important for getting more out of your day. If you always have the perfect amount of energy to work and think straight, you will work more productively.
HIIE changes the way your body processes energy both immediately after exercise and in the days following. A total of 3-4 minutes of high intensity exercises of just 30 second bouts throughout the day has been proven to show positive results. Full body exercises using your legs are fantastic as your leg muscles are the biggest in your body and are found to influence insulin sensitivity. With increased insulin sensitivity your muscles have more glucose available to produce energy. Blood glucose levels are positively influenced (up to a 25% increase) even up until 24 hours after a series of HIIE. It is so important to include some HIIE in your workout program often as these benefits are no longer apparent after 72 hours of being sedentary. To come back to reality quickly, this means full body high intensity intermittent exercise every 24 hours will sustain your energy levels at a more consistent level.
Of course there are dietary factors which also influence your blood sugar levels; however exercise is a great way to make a difference.
Catecholamine release is drastically increased with short, high intensity bouts of exercise. The process of lipolysis is enhanced, thus the breakdown of fat stores in your body occurs more efficiently. So in theory, this will decrease your adipose fat, leading to a slimmer waist line, right?
One study found that just 7 sessions of HIIE over 2 weeks increases a woman’s ability to use fats as a fuel source during exercise. In addition to this, studies have found that after exercise, your energy helping hormone levels remain elevated. This means your body’s ability to break down fat is enhanced for every activity you do for some time after exercise.
HIIE has repeatedly shown greater weight loss when compared to an aerobic only program (cardio). With just 3 HIIE exercise sessions per week, you can lose kilos of fat off your stomach.
If you regularly do HIIE your body will remove that fat more efficiently, always! Who doesn’t love doing less to achieve more?
Use your muscles more efficiently
Growth hormone has an effect on the way proteins are stored and used in our bodies. This means, the way our muscles develop. GH presence is considerably increased after HIIE which means your muscles have a better chance to grow and become more efficient. Studies have proved that those trained in high intensity exercise such as sprinters produce a greater GH response. This means the more you participate in HIIE, the more benefits you will see from a muscular efficiency and development point of view. Maybe your muscles will become more toned, or perhaps you will be able to run faster or walk up more stairs before feeling fatigued.
Grehlin is a hormone which plays a vital role in when you feel hungry. As a response to exercise grehlin is inhibited meaning your brain is not stimulated with thoughts of food and hungry feelings. High intensity exercise only enhances this effect. Immediately after a burst of exercise where your heart rate is high and you feel a degree of fatigue, you will no doubt have no feeling of hunger. The effects on blood glucose levels immediately post high intensity exercise also play a role in suppressing hunger. Diet plays such a huge role in weight management. You can control your hunger through exercise without realising it! How amazing is it that just a few minutes of exercise could cut out that cheat snack you would otherwise have eaten.
Work more productively and efficiently
One of the major reasons why I currently love high intensity exercises is that it allows me to do more work in less time. With a series of 2 minute micro workouts dispersed throughout the day I am able to maintain a consistent high energy level (due to hormone stimulation and consistent blood glucose levels) and remain mentally stimulated. To put it simply, I work more efficiently therefore get more done in less time.
Those of you who are strapped for time will love a HIIE program. You will work out for a shorter period of time and see repercussive results throughout your day. I will say it again – who doesn’t want to achieve more by doing less?
With the right mental attitude and lifestyle factors, high intensity intermittent exercise can be a fantastic way to lose weight, have more energy and feel fantastic!
If any of you are interested in reading more in depth on this topic, check out this review article http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2991639/pdf/JOBES2011-868305.pdf.