What it is
High intensity interval training or HIIT training is a form of exercise involving short bursts of intense work, followed by short recovery periods. There are various versions of HIIT sessions all with different work and rest timings. The idea is that you work as hard as you can in the short time frame and have a quick recovery before repeating the intense work. Exercises can be simply body weight- such as press ups, burpees, high knee sprints etc, or weighted- including clean and press, shoulder press, barbell squats. The options are endless as to how to fit your programme, depending on what you want to achieve.
1. Fat loss
Due to the high intensity nature, your metabolic rate is dramatically increased, not just during the class but in the 24hours to follow. Therefore you burn up calories faster and more efficiently for longer.
By pushing into that anaerobic zone you increase your lactic threshold (the point where lactic acid builds up). This means you are less likely to feel that burn and so can continue to work harder for longer. You will also improve your heart functioning ability (cardiovascular efficency). Your body becomes better at transporting oxygen around the body, allowing you to work harder for longer ie. increasing your fitness levels.
3. Burn fat not muscle
Unlike regular cardio exercise, HIIT training has been proven to burn only fat and not muscle. This means you can work hard in the gym and not feel your cardio based workout is ruining it.
4. Ease of access
HIIT workouts can be done anywhere and any time. They are only 30 minutes long so do not require you to take large amounts out of your day. Also, the short nature of the class means you can work harder because you know it will be over soon. Finally, no equipment is required if you do not want. All you need is a timer to keep track of work and rest intervals.
I absolutely love HIIT training. For me, it is perfect! It is fast paced whilst not going on for too long which, unlike some classes, keeps me totally motivated the whole way through. I do enjoy it, but the best thing is that it really does work. It gets you fitter, faster than any other programme and decreases body fat percentage after only a few sessions. I try to do HIIT 2 or 3 times a week. I fit it in between my gym sessions and as it does not burn muscle, it compliments them so well. HIIT makes me feel fitter, healthier and slimmer. I just can't get enough!
Les Mills Grit
As a Grit instructor, I have to take this opportunity to publises it's programme. There are 3 versions of Grit which one can take part in, depending on goals. They are all forms of HIIT but focus on slightly different aspects.
Grit cardio requires no equipment as all exercises are body weight. Examples of exercises are mountain climbers, high knee sprints, bear crawl. Goal is primarly fitness and fat loss.
Grit Plyo is a plyometric focussed form of HIIT training, meaning it is probably the most intense. It works on explosive power including some body weight and some weighted exercises. Such include explosive jacks, plyo press ups and squat jumps. This is guaranteed to get you working to your max!
Where can I do a HIIT session
There are many different forms of HIIT training in and around the exercise world. Here is a short list of different classes that follow an interval training regime. Look out for them in your local gyms.
Metafit - various body weight exercises with different work and rest times
Les Mills Grit - various weighted/body weight exercises with changing work/rest circuits
Insanity- various body weight exercises with slighly longer work periods
HIIT- Various body weight exercises with varying work and rest times
Tabata training - various exercises of 20 seconds work followed by 10s rest for 8 rounds.
If you want to conduct your own HIIT session all you really need is a timer. Chose your intervals and exercises and take part wherever you like. A great app that I use is Seconds Pro. You can create your own interval times and it will count you down from 3 before the next time frame so you know when to start. You can also add music to keep you motivated.
When forming your own HIIT programme, a useful hint is to alternate exercises between upper and lower body. Eg. 30 seconds squats, 20 seconds rest, 30 seconds press ups. This means your body has to work even harder as it adapts to redirecting blood to different parts of the body in a short time frame. Over time, you become more efficient and in turn fitness levels increase.
It is also best to keep your session to under 30 minutes. Any longer than this and you will not be able to sustain the insensity. Also, when chosing interval times, you want to work up to a point that within a partuicular circuit of x number of rounds, rest periods are shorter than work periods. eg. 30 seconds on, 20 seconds off. However, between rounds, rest periods should be longer. eg. 1 minute.
Remember, only you know your fitness levels. Therefore, when creating your own HIIT workouts, you are in charge of picking a rest time that reflects how long you need in order to work at the same high intensity throughout. If this means you need to rest for longer, then go for it. eg. 30 seconds on, 30+ seconds rest. The goal is to work at the highest intensity possibly in those short bouts.
I could not reccommed HIIT training enough. Please do get in touch if you have any other questions or ideas about HIIT. Give it a go, it really does work!!!