One of the greatest buzzwords in world of fitness and weight loss is High Intensity Interval Training or simply HIIT. This exercise has potential to allow an exercise to lose weight faster than any other form of aerobic exercise. Interval training is not new in the field of sports conditioning, it has become a popular form of exercise for general conditioning and weight loss. Following are some basic information on HIIT and explains why this form of exercise is very effective for weight loss

The Power Output

To understand the benefits of HIIT, it is important to first understand some basic principles and concept of power. Generally speaking, power is a measure of the ability to perform work per unit time (Work/time). Work is defined as the amount of force required to move an object a certain distance (Force x Distance). So power is defined by the following formula: Power = Force x Distance/time. If you recall that velocity (speed) is equal to distance divided by time (Distance/time), then it is easy to see that power is actually a measure of how fast you generate force.

Power output and energy expenditure

Obviously from the previous explanation, it should be clear that the amount of energy required to perform a task is dependent directly on the power required to do so. So if applied specifically to human exercise, we recognize that muscles use chemical energy produced from the food we eat to generate power. Consider the muscle power required walking 3 miles per hour and that required running at 11 miles per hour.

The muscle power required in each example is strictly dependent on the speed since the body weight being moved changes very little and essentially remains constant, assuming sufficient hydration. It is possible however to regulate power output by other variables other than speed by manipulating the amount of force (wearing a weighted vest) or increasing the resistance to movement like increasing the gradient of a treadmill or running up hills.

What is HIIT?

HIIT involves performing bouts of high intensity running normally 1 to 3 minutes separated by recovery periods of walking for about the 2 to 3 times the duration of the running bout. The work - recovery ratio should therefore be 1:2 or 1:3. The intensity of the running portion should be near your maximal oxygen uptake.

Since most casual exercisers and those looking to lose weight rarely know their maximum oxygen uptake, is may be helpful to use a perceived effort scale of 1-10 to regulate intensity; with 1 representing no effort, and 10 representing absolute maximal effort. Aim for about 8-9 on the effort scale.

Note that HIIT describes what it is HIGH Intensity Interval Training so before you begin such a regime it is advisable to have yourself cleared by a physician.

How do I begin HIIT?

There is no hard and fast rule to HIIT other than those mentioned earlier. The basic principle of HIIT is to manipulate intensity to increase power output and accelerate weight loss. Initially if you are just beginning HIIT, your work sessions may be much shorter than 2 to 4 min.

As you become more conditioned, you may also start to increase the intensity of the sessions by aiming for the higher end of the perceived effort scale or by reducing the recovery periods or both. If you plan to workout on a treadmill or elliptical machine, the best way to perform HIIT is to choose an intense interval or hill program. If you prefer to end the session quickly as possible, you can manually adjust the speed and incline randomly depending on your effort. If you are sadistically self-destructive, you may try running the hills and walking the flats on a treadmill, this will dramatically increase your power output and energy expenditure.

Experiment with these techniques of manipulating the intensity of your workout and depending on your level of fitness, the entire interval training session should last from about 10 to 20 minutes.