A simple definition of Interval Training is: short, high-intensity exercise periods alternated with periods of rest. These higher and lower intensity periods are repeated several times to form a complete workout. Here's a basic example: walk for 5 minutes at 3.5 MPH, walk for 1 minute at 4.2 MPH and then repeat this sequence several times.

Most people spend their workout time only performing continuous training exercises. These are exercises where the intensity level is basically constant throughout. An example of this is walking at 3.5 MPH, at 0% incline for 30 minutes.

Continuous training is very effective and should not be eliminated from your weekly workouts. However, it's recommended that you include both Interval Training and continuous training sessions as part of your fitness regimen.

Why should you include Interval Training? As previously mentioned, there are many benefits to this type of training and execution is relatively simple. Interval Training can help you improve cardiovascular fitness, increase speed, improve overall aerobic power, burn more calories, break-through a plateau, increase workout duration, reach new exercise levels, expand your workout options and increase your workout threshold - just to name a few.

Plus, this training method has useful applications for beginners, intermediate exercisers and even conditioned athletes. There are two basic types of Interval Training. For the majority of exercisers (novices and intermediate) Fitness Interval Training methods are recommended. Athletes can choose a more advanced technique known as Performance Interval Training.

The Fitness training method utilizes periodic increases in intensity. Typically the higher-intensity levels range from 2-5 minutes in duration and are followed by lower-intensity periods that also range from 2-5 minutes. And, a critical element in Fitness Interval Training is determining the appropriate level for the higher-intensity periods. This level should not exceed the anaerobic threshold (which is usually reached below 85% heart rate reserve).

On the flip side, the Performance training technique involves periods of near maximal or even maximal intensity (e.g. >85% heart rate reserve - even reaching 100%). The higher-intensity levels can range from 2-15 minutes in duration and are followed by lower-intensity periods that also can range from 2-15 minutes in duration.

Don't let the two types of training and their ranges confuse you. Incorporating Interval Training methods into your exercise routine is actually quite easy. Since the majority of exercisers fall into either the beginner or intermediate category, we'll focus on getting started with those techniques.

To! begin, choose the type of exercise: walking, jogging, swimming, biking, etc. Next determine your lower-intensity level. This is usually somewhere between 50-65% target heart rate. This will be your baseline, lower-level intensity. Then simply increase the intensity-level up to where you feel like you are working hard to very hard, but avoid reaching a level over 85% target heart rate. If monitoring your heart is not feasible, instead use the RPE scale where 1 is basically at rest and 10 is working extremely hard. For example, if you find that when you are exercising at a comfortable level you rank a 5, then bump up to a 7 for the higher-intensity intervals.

You may choose to systematically raise and lower your intensity (e.g. 2 minutes lower intensity followed by 1 minute higher intensity and repeat) or you can alternate more randomly by raising and lowering the level at your discretion. To increase your intensity, you may choose to change the speed, incline, or some other variable. ! Interval Training can be especially helpful in situations where you are trying a new form of exercise. For example, this can be very beneficial when first learning to jog. If you attempt to jog continuously without building up to it, you will probably fatigue quickly and even give up. However, if you begin with intervals of walking interspersed with jogging periods, the workout will be much more enjoyable and effective. Also, you will be more likely to stick with the program and achieve the end result - continuous jogging.