Plyometrics is a method of training devised to develop a person’s explosive muscular power. Power is a component of fitness that combines the components strength and speed.
Plyometrics is aimed at making muscles work more efficiently, rather than making them bigger. It was developed in the mid 1960s by a Soviet physiologist Dr. Yuri Verkhoshansky, the daddy of Plyometrics.
The concept, the science, the jargon…
Plyometrics combines explosive movements that condition the muscles. It does so by rapidly stretching a muscle (eccentric) and then rapidly shortening it (concentric). Scientifically, it is known as the “stretch shortening cycle”. This cycle involves three phases; the pre-stretch (phase one – eccentric), then the delay between the eccentric and shortening (phase two – amortisation the most important phase) and finally the actual contraction (phase three – concentric). The shortening of the muscle prompts what is known as “myotactic” or more commonly, stretch reflex of the muscle.
This stretch reflex involves the brain and plyometrics teaches the brain to activate muscles differently. It increases the activity in the muscles undergoing the stretch, allowing it to contract more forcefully. Normally the brain is conditioned to limit the force of a stretched muscle. Meaning a stretched muscle could be in danger, the brain sends warning signals to the contracting muscle to stop stretching, thus preventing injury. Therefore, plyometrics can condition the brain to activate the muscles differently, thus developing the stretch reflex.
Link – If the concentric muscle action does not occur immediately after the stretch, the potential energy produced by the stretch reflex response is lost. For example, you are about to jump, you dip (phase one), whilst in the dipping position, you pause too long, the potential energy the muscles generated decreases (phase two), resulting in your not being able to jump as high (phase three).
Why Jump On it?
Numerous research studies have shown that plyometric training will lead to physical adaptations such as increased muscle strength, improved transmission speed of signals to and from the brain to the muscles, quicker running speed, increased bone density (stronger bones) and reduction of the force imposed on joints, thus providing joint protection.
Plyometrics isn’t for everybody and is deemed strenuous. As with any training programme, it comes with some risks, such as increased risk of injury, especially if you don’t have adequate strength to start with.
If unsure, always consult a qualified trainer, who should assess and address your needs. For those of you thinking, ” I train regularly” – note: Just because you are training doesnt make you safe; any programme involving explosive movements is associated with a higher risk of injury. Ensure you have established a base of strength and flexibility before doing any plyometric programme. Like anything in life, it has to be habitual and takes time to develop.