Interval Training is a method of training originally popularized by Emil Zatopek that is what it says. Running intervals simply means to run fast for some time or distance separated by intervals of easier running. Traditionally if the periods are measured by time the interval training is known as a Fartlek.

Intervals are a popular track workout. For example, when someone says they are running 400s or 200s they generally mean that they are doing repititions of faster 400 or 200 meter distances separated by a period of rest of slower running. A related workout is a ladder, which consists of increasing then decreasing intervals in the same workout.

As many will be quick to point out, this kind of training is called Interval Training, for a reason, and, indeed, one of the most important factors is the length and intensity of the rest periods. Some argue that these periods should be kept quick to best simulate racing a longer race, while others argue that the focus should be on the faster speeds between intervals. Either way can lead to a tough workout and generally the specifics of an individual's interval training will depend on the goal race distance and personal preference.

Interval Training Quotes

• "Why should I practice running slow? I already know how to run slow. I want to learn to run fast. Everyone said, 'Emil, you are a fool!' But when I first won the European Championship, they said: 'Emil, you are a genius!'" - Emil Zatopek