If you've had a significant amount of base training and want to run faster, this article is for you. This excellent excerpt reprinted with permission from Human Kinetics of Triathlon Workout Planner by John Mora

"Intervals (also known as repeats) are short bursts of speed repeated over a measured distance with recovery periods between each interval. As I discussed in the previous chapter, intervals are a key component of training for swimming and running. In this chapter, we’ll further explore 80/20 running workouts and also learn how to apply interval training to cycling.

Elite runner and author Jeff Galloway once wrote, “Intervals are based on a simple principle: The only way to run faster is to run faster” (Galloway 1984). Although that premise is true, there are some specific guidelines to interval training that can help you prevent injury and get the most out of your hard work.

* Base training first. Never begin any kind of speed work without a year’s solid base of consistent distance running. Intervals are demanding and can be very rough on your body, so it’s important that you’ve developed the muscle strength and joint integrity to support the effort.

* Set a baseline with a time trial. It’s a good idea to start off your interval training with a performance benchmark that tells you