Stretch-shortening cycle (Plyometric) and a few other things
During my last blog I mentioned that I would explain (well at least try) the Stretch-Shortening Cycle (SSC). It would be a lot easier to explain this in scientific terms and by trying to explain it more layman has made my job that little bit harder in my opinion. But fear not, I will try my best – I’m sure those who are educated enough will find some errors but were all here for learning.
I suppose I should first put SSC into context – most if not all are aware of plyometric training/exercise, well SSC is a part of plyometrics (in fact most sports also). There is many written on plyometric training, and I’m sure we can all agree that the purpose of training plyometrics is to improve the production of not only muscle force but power. As with everything there is a process that is undertaken to produce this force/power. In essence the plyometric movement is a rapid eccentric movement followed by an immediate concentric muscle action, well during this process something called the series elastic component (SEC) occurs (this being the fundamental part of plyometric exercise). This process mostly uses the tendons - when the muscle is stretched (eccentric - see last blog) the SEC acts as a spring (think elastic band being pulled apart) – during this phase elastic energy is stored. Once we engage an IMMEDIATE concentric muscle action the stored electric energy is released, this therefore contributes to the total force produced by the muscles and also allows the muscle/tendon to return their unstretched position. This process also makes up the SSC with an added two phases known as Parallel Elastic Component (PEC) and Contractile Component (CC). What the SSC does is in fairness pretty basic – and I suppose I could have just written this in one sentence and been done, but the SSC employs the stored energy within the SEC and the stimulation of the stretch reflex facilitate maximum increase in muscle recruitment over the shortest period of time. This process relies heavily on time and motion – to long and to greater motion on the joint and the elastic energy will simply disperse through heat.
While the above may seem somewhat tongue tied – it is very relevant to the SSC process – but why do so many people harp on about it, and why is plyometric so important. Well I feel the answer is pretty simple, most if not all sports rely on something being done as quickly and as powerfully as possible. One of the best examples being long jump – try jumping far as slowly as possible? You can’t. Most sports require explosive movements and if we can recruit more muscle fibres per movement and utilise the elastic energy stored to boot then we stand a better chance of success.