Escalating Density Training

Escalating Density Training (EDT) is a training protocol developed by Charles Staley sometime around 2002, and which has taken off tremendously in that time. As the name implies, EDT factors in training density—the amount of work you do in a given time frame. You see, Staley looked at training and muscle growth in a whole new way, at least relative to how much.While we generally look at mainly load (weight) and volume (sets x reps), with EDT, Staley looked at density—that is, the total amount of work completed within a specific time frame; each successive workout, you aim to achieve more work in that same time period (escalating density, get it?). This was progressive overload in a whole new way.

Procedure

Each workout consists of two 20-minute time frames separated by a short (5-10 minute) rest period. In each time frame, you’ll perform two exercises, for a total of 4 exercises per workout.
In each time frame, the two exercises are performed in alternating fashion, back and forth, until the time frame has elapsed.

After warming up the first two exercises, select a load that approximates a 10-12 RM for each exercise. Ideally, the weight used for each exercise should be equally difficult.
Sets, reps, and rest intervals: Generally, most people will find it most effective to do higher repetition (but not maximal effort) sets and shorter rests at the beginning, and then gradually progress to fewer reps per set and longer rests as fatigue accumulates.

As an example, you might begin by performing sets of 6 rep with very short (15-30 second) rests. As you begin to fatigue, you’ll increase your rest intervals as you drop down to sets of 4 reps, then 2 reps, and as the 20-minute time limit approaches, you might crank out a few singles in an effort of accomplish as many repetitions as possible in 20 minutes.

NOTE: Do not perform early sets to failure, or even near failure. My recommended starting point is to do 1/2 of what is possible (e.g., 5 reps with a 10-RM weight) at the beginning of the time frame. As the time limit approaches however, you’ll find yourself working at or near failure as you attempt to break your rep record.

Progression: Each time you repeat the workout; your objective is to simply perform more total repetitions in the same time frame. Apply the 20/5 rule: as soon as you can increase the total number of reps by 20% or more, start the next workout with 5% more weight and start over.
And that’s essentially it. No pre-ordained numbers of sets, reps, or rest periods. It’s entirely up to you. Your job is only to complete the 20-minute work period, and then improve on it the next time around.

While I am not sure I'd go so far as to say Staley completely revolutionized training, I can say with certainty that he gave us a revolutionary training method. EDT was different than anything else at the time, and I've used it myself and with and a lot of my clients for rapid muscle growth. The workouts are quick, easily quantifiable in terms of progress, and have something that I always try to incorporate into my programs: a built in, intuitive method of progression.

For advanced trainees, and anyone trying to put on some mass, EDT is an exceptional option.

http://www.schwarzenegger.com/fitness/post/the-basics-of-training-for-size-part-3-cutting-edge-modalities-for-accelera