Mick McDermott is currently the Fitness Coach with Al Nasr FC, Dubai. Prior to joining Al Nasr FC, Mick was an Assistant / Fitness Coach with the Iran National Team during their World Cup preparations and also spent 5 seasons with Al Ain FC. Mick, originally from Belfast, N. Ireland, spent 12 years playing and coaching in the US prior to joining Al Ain FC. Mick holds both UEFA and USSF ‘A’ Licenses and is a co-founder of the SoccerSpecific.com website.
Plyometric Training
Most soccer players and coaches are familiar with the term “plyometrics” however, for many, confusion exists as to how and why plyometrics can be used as a performance enhancing technique.
Plyometrics can be traced back to Eastern Bloc countries of the 1960’s. Coaches and athletes in these countries reaped the benefits of incorporating “jump training” into their training regimen. For around 20 years plyometrics were solely within the realm of track and field athletes and it wasn’t until the 1980’s that other sports such as soccer began to develop and integrate this method into their training system.
Simply put, Plyometrics refers to activities that aim to improve a player’s power output through movements involving maximal muscle contractions at very high velocities. ‘Ground contact time’ is the key to plyometric training for soccer players. When running, jumping, turning etc. contact is made with the ground. Upon striking the ground the muscles surrounding the ankle, knee and hip lengthen (eccentric contraction) to absorb the impact. These same muscles must then contract (concentric contraction) rapidly in the opposite direction to allow the player to jump, change direction or simply to continue running. The period of time between the eccentric contraction and the rapid concentric contraction can be considered the ground contact time. It has been shown that with a well-designed plyometric program the ground contact time can be reduced resulting in a player who can jump higher, accelerate faster and change direction quicker.
But how does it all work?
There is a two-pronged answer to this question.
Firstly, within our muscles receptors known as muscle spindles detect the rate of changes in muscle length. When a muscle is quickly stretched these muscle spindles cause a rapid contraction of the same muscle. The muscle spindles detect the rapid stretch (lengthening) and as a protective mechanism against tearing cause the muscle to reflexively contract (shorten) in the opposite direction. This is termed the stretch reflex.
The most commonly known application of this physiological response is the knee-jerk test performed by doctors. The doctor taps on the patellar tendon just below the kneecap causing a small but rapid lengthening of the thigh musculature. The resulting contraction of the thigh musculature causes the reflexive knee-jerk response.
Secondly, our muscles possess a certain amount of elasticity. Just like rubber bands, when a muscle is stretched energy is stored. When the muscle (rubber band) is released the stored energy results in a more forceful return to its original length. The greater the velocity the original stretch is applied the more ability the muscle has to develop greater force.
The goal of plyometric training is to enhance both the stretch reflex and the power producing qualities of the series elastic component of muscle fibers, which should in turn have a positive effect on sports performance.
It is important to assess a players training age, level of maturity, level of conditioning and strength base prior to embarking on any plyometric type activities. Advanced athletes are capable of performing high shock activities whereas pre-pubescent athletes will be better served with low intensity hopping and jumping.
To end, studies have shown that plyometric training can have a positive effect on sports performance. As with any new form of training safety should be the first priority. Coaches and players should seek the advice of a qualified instructor prior to beginning any new training regimen.