Interval Training

In general terms, interval training refers to the use of higher intensity work intervals interspersed with recovery intervals, or rest intervals. The length of the work and recovery intervals can vary depending upon what training effect you are trying to achieve.

Running coach Jack Daniels used the term intervals in a more specific way to refer only to VO2max or race pace intervals of 3-5 minutes in duration. He uses the term reps (repetitions) to refer to work periods of less than 2 minutes in duration at highest intensity.