What is Pyramid Training?
Pyramid training is a method of training in which, heavier weight is used on each progressive set. The theory behind this principle is if your body moves heavier loads, the bigger and stronger you will be. Each week you need to increase the weight you use based on your one rep max for that exercise.
Determine you One Rep Max:
http://www.naturalphysiques.com/18/one-rep-max-calculator
The best approach is to end up at 75% of your one rep max, for 8-12 reps, on your last set.
Pyramid training maximizes muscle growth. The increased amount of weight, in every set, stimulates your muscle to grow larger in order to handle the load better next time.
Why is Pyramid Training So Effective?
It forces your body to step up to the challenge, and move heavier weight. The stimulus pyramid training imposes on the body, allows continual improvement in muscle mass and strength.