ATLETA Fitness

Plyometric Training – Exploring the Benefits

Think back to your youth, back when you were a little younger and just a child. Remember all the climbing, jumping and running you used to do? Constantly moving and being active? If only there was a way to go back, harness that energy and power, and bring it back to life again in your current self! Well, luckily there is a way…

Plyometric training utilises the natural spring of the tendons to create elastic potential energy, which is then translated into mechanical energy and muscle action as we jump or ‘explode’ into a movement. Every time you swing your arms and ‘load up’ before you jump, you’re applying a plyometric technique to help enhance your peak jump height. So what exactly does all this mean, what is it useful for, and how can we improve it? Let’s explore plyometric training further.

Box JumpsPlyometric training, the Stretch Shortening Cycle and power Production

In simple terms, plyometric training is the art of using the elastic potential of our muscles and tendons to create a more powerful muscular contraction. Think of this as similar to using a resistance or rubber band to assist a push-up or chin-up motion. How this occurs is through an action known as the Stretch-Shortening Cycle (SSC). Let’s break this down into a simple 3-step process, and take the example of a simple counter-movement jump (CMJ) to illustrate the SSC.

Eccentric Phase:

This is the first phase of the SSC. Eccentric muscle contractions occur when a muscle lengthens under tension, such as the hamstring muscle lengthening as your leg lands during a running stride. In this case the hamstrings are not working concentrically to push you off the ground, but rather working to slow down the rate of stretch as you land. The muscle is therefore working to control its own lengthening, as opposed to a standard muscle contraction (concentric) where the muscle shortens to produce force.

During the eccentric phase of a CMJ you quickly bend your knees and throw your arms back in an effort to create elastic potential energy. This is then stored in the musculo-tendinous unit ready for the second and third phases of the SSC, where the stored elastic energy will be utilised to complement, assist and improve the concentric muscle contraction (the jump).

Amortization Phase:

This is the period of time that occurs between the eccentric and concentric phases of plyometric contraction, during which time the afferent (input) and efferent (effector/motor neuron) nerve pathways carry information to and from the dorsal and ventral roots (respectively) of the spinal column. If the amortization phase takes too long to complete, ie there is too long between the elastic stretch and the concentric muscle action, then all elastic potential energy is lost as heat and rendered useless. Therefore, it is important to keep the amortization phase as short as possible.

Concentric Phase:

plyometrics phasesThis is the actual jumping phase, where the muscle contracts to create an upward force and jump motion. Three forces are at work here to contribute to the jump force: the concentric muscle action, the elastic potential of the musculo-tendinous unit and the stretch reflex stimulated by the muscle spindles. The elastic potential allows the muscle to return to its original length faster and more effectively than through pure muscle contraction, resulting in a larger force being applied through the jumping motion by the musculo-tendinous unit. The stretch reflex is the third action contributing to the increased muscle power output here, which is the hardest action to describe. Effectively, muscle spindles lie in the muscle belly and detect changes in muscle length, relative to time. If a major change in muscle length is felt over a short period of time, such as when an ankle starts to ‘roll’, the stretch reflex kicks in and stimulates an opposing (antagonistic) muscle action to ‘right the wrong’, and bring the lengthening muscle back to normal length.

In the case of our jump, the quick counter-movement before the jump results in a large, quick change in length of the lower limb muscles, and the stretch reflex then seeks to rectify this by stimulating a reactive muscle action. This reactive muscle action aids that of the jumping action, as a synergist to the CMJ.

These three steps sum up the how of plyometrics and muscle power production, but what is it useful for and how can we use this tool for our own training?

How is plyometric training useful

In simple terms, plyometric training is the most effective way to develop speed and power in the body. It relies heavily on muscle, tendon and neurological (nerve) function, making it an extremely functional style of training. Speed and power is a useful attribute for all populations, from office workers through to elite athletes. Power is a protective factor against injury in elderly populations, as the ability to develop power is what helps you ‘catch’ yourself, or adjust your muscle position when you trip over and hyperflex/extend certain structures (stretch reflex). Developing power in general populations can help them remain injury free, and improve bone mineral density and strength (as it is a weight bearing activity).

Power development is also an extremely important athletic attribute. High performance sport generally relies on a player’s ability to quickly create power, and explode into game situations. For this reason, plyometric training makes up a large base for many professional athletes, particularly in short duration events or in intermittent team sports (such as soccer, AFL or Rugby).
Plyometric training is, however, also one of the most fatiguing styles of training due to the high metabolic, muscular and neurological strain. Large rests are needed between plyometric sessions to allow the body to properly adapt and recover.

What exercises do we do for plyometric training?

PlyosEffectively, plyometric training just requires large force production over a short time period, but requires the pre-stretch (SSC) to generate the elastic potential energy required for the explosive contractions. Due to the high stresses involved, plyometric sessions are not broken up into ‘sets and reps’ as such, but total load is calculated based on the total amount of movements and landings involved during the session. Beginners should aim to reach 60-100 landings in a session (think of that as 3 sets of 10 box jumps, 3 sets of 10 standing long jumps and 2 sets of 10 clap push-ups).

Some great plyometric exercises: box jumps, depth jumps, standing long jumps, explosive lunges, bounding, clap push-ups, clap chin-ups, rope or medicine ball slams, squat or medicine ball thrusters and a host of other exercises. Many ‘standard’ exercises can be made into plyometric exercises by incorporating the fast pre-stretch action, and completing the exercise explosively.

Need more information, or help getting started with some plyometric training? Get in contact with our team today to start you on your path towards improved power! Whether for higher performance sport or purely for a great workout, plyometric training is guaranteed to induce massive fatigue and post-workout soreness, coupled with great results! Our trainers are all degree qualified and highly experienced with a wide variety of exercise protocols. With affordable training that fits to your goals, why not come along and give it a go!

Written by Johann Ruys

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