I have been following Field Strong for almost 6 months. The strength and speed gains I have made are like nothing else I have been associated with. I came from a well publicized program that did nothing to make me faster or more explosive. Sadly, the last 6 months made me realize how far off I really was. In your present training cycle, you keep talking about Compensatory Acceleration and bar speed being vital to helping an athlete get faster and more explosive. What is one thing I can implement to move the bar faster and help me become the athlete?


John-Welbourn-Amortization-PhasePower is the ability to quickly produce large amounts of force, or what I refer to as, your ability to display your strength dynamically. A key component to this is the amortization phase, or commonly known as the transition phase. This is one of three phases of dynamic movement: eccentric, amortization and concentric.

This phase of movement refers to the bridge between the eccentric and concentric phases. The amortization phases uses the stretch shortening cycle (SSC) in production of power, as the length of amortization is a vital component in your ability to display your strength. If the amortization phase is slow, the energy stored during the eccentric phase dissipates, thereby reducing the effect and killing power.

The squat is an easy way to understand the phases: eccentric, amortization and concentric. When an athlete eccentrically loads the squat, the muscle is stretched (lengthened), storing energy in the elastic components of the muscle. So as the lifter descends this begins the eccentric phase. His ability to transition from eccentric to concentric becomes a key factor is in his ability to display his strength. We refer to an athlete’s ability to drive out of the bottom of the squat as starting strength or reversal strength.

When performing compensatory acceleration (1) movements, an athletes ability to transition between eccentric and concentric movements with a fast amortization phase becomes the limiting factor when speed is the goal.

When utilizing compensatory acceleration into the training, an athlete must keep accelerating the bar as the mechanical advantage increases. But in the ever present goal to increase bar speed, an athlete must try to increase the speed of the lift while at the least advantageous portion of the lift. Therefore you must try to speed up the eccentric and transition phase of the movement, if you are to have any chance of moving the bar at the rate needed active type II muscle fibers and attain speed in and out of the weight room.


(1) Hatfield, Fred – POWER – A Scientific Approach (1989)