Before every jump an athlete performs, there is a quick lowering (eccentric) motion followed by a transition from lowering to rising (amortization phase). Several recent studies have suggested (and our observations over the past 15 years suggest the same), that increasing ones ability to overcome the eccentric and transition phase more rapidly can improve the rising (concentric) phase due to increased peak force and power (JOSCR – Vol. 26 #9, Sept. 2012 pg 2345).
We usually start off with rhythmic squats and landings from sub maximal jumps, to allow us to focus on the movement and technique (getting into positions that they can accelerate out of). This rhythm promotes confidence and sets the stage for more aggressive exercises. Next we begin to increase the loading with light dumbbells and/or medicine balls as we squat or lunge down to a ‘pause’ where we hesitate in power position (jump ready position or the position in which they feel most ‘explosive’), then we have the player accelerate vertically out of this ‘pause’ as quickly as possible in an attempt to improve the rate of force production.
“The stronger we get (more weight we lift in squat-like motions) the better prepared we are to absorb the landing (or quick lowering / eccentric forces) and transition to explosive vertical jumps.”
Over the next few weeks (or months in some cases) we will decrease the emphasis on the ‘pause’ and increase the load which will get us stronger in the eccentric phase. The stronger we get (more weight we lift in squat-like motions) the better prepared we are to absorb the landing (or quick lowering / eccentric forces) and transition to explosive vertical jumps. During this time we are also transitioning our plyo program from rhythmic landings to quick landings to pause, or ‘stick’ as we like to call it. It takes good levels of coordination and strength to jump at max height and stick the landing in power position (ready to jump again).
Once we have reached adequate levels of strength and technique we go into the 3rd phase of our plyo program – Stretch Shortening Cycle (or SSC), where we are working on improving the amortization phase (transition) by decreasing the ground contact time (GCT) and increasing the rate of force development (RFD). The stronger our athletes are in the eccentric phase (given that they also have developed good technical jump mechanics) the quicker they can get into and out of these positions which lead to decreased GCT and increased RFD.