When discussing plyometric training the term ‘stretch shortening cycle’ is often mentioned – but what is it? And how can it be utilised to achieve optimum results?
Here is a quick read on the stretch shortening cycle. What is it? And how does it work?
The Stretch Shortening Cycle
The Stretch Shortening Cycle (SSC) is the body’s natural way to stretch, and so store energy. The benefit of this cycle comes by using it in addition to your body’s own muscular strength. So, the larger the muscle, the bigger the stretch and the more energy that can be stored.
How this works
The stretch shortening cycle involves two phases of muscular contraction
- Eccentric phase – muscle lengthening under tension
- Concentric phase – muscle shortening
The pre-stretch of the muscle causes it to be eccentrically lengthened. With this, tension is built in the muscle – similar to a rubber band when stretched. The longer the time the pre-stretch is held, the less tension is stored in the muscle. The shorter period of time for the pre-stretch, the larger the amount of tension.
This stored energy helps increase the strength of the following contraction.
And so, the faster the muscle is stretched eccentrically, the greater the force will be on the following concentric contraction. For example, a quick ankle tap creates the tension necessary to create height off the floor.
Have a go yourself –
- Take a rubber band or hairband and hold the band stretched for 5 seconds then release. Notice the small distance the band has travelled. Now, in one movement take the second band, pull back and release. You will note that this band travels a lot further. This is because the second band has not lost tension in the period it is held in, therefore it has a larger amount of tension.
- The same principle applies when looking at a squat jump (SJ) in comparison to a countermovement jump (CMJ). Sit in a Squat jump and hold this squat position for 5 seconds. After 5 seconds, release and jump. Next, perform a quick countermovement jump. You will notice that when you performed a CMJ your jump height was greater.
So, the faster the contraction, the greater the output. This is why, in plyometric training, top strength coaches are looking for quick floor contact time. This achieves results and could make all the difference in a game of American Football if you can jump just an inch higher to make an interception.
More about plyometric training to follow!
If there is anything specific regarding plyo exercise then comment below!