Fundamentals of power and plyometric training

Man throwing medicine ball to floor

What is muscular power?

Muscular power is different from muscular strength. Muscular strength is the amount of force that your muscle can produce, whereas muscular power is the amount of simultaneous strength and speed that your muscle can produce. For example, if you were to lift a heavy barbell off the floor, it would be a demonstration of strength. On the other hand, if you were to snatch the same barbell from the floor and lift it over your head in one swift movement, that would be a demonstration of power.

How is muscular power developed?

The way to develop the different muscular properties (size, strength, endurance, or power) is explained in detail in How many sets and reps should you do?, in the Weight Training Guide. In short, muscular power is developed by performing exercises that involve rapidly generating a large amount of force. Power exercises for the lower body often involve hopping and jumping (for example, the broad jump [YT] and box jump [YT]). Exercises for the upper body usually involve barbell weightlifting movements (for example, the snatch [YT]), as well as advanced push-up variations (for example, the clapping push-up [YT]), and rapid medicine ball catching and throwing actions (for example, the standing medicine ball chest throw [YT]).

What is plyometric training?

You will often hear the word ‘plyometric’ being used to describe power training, especially jump training. However, true plyometric training is a little different. It is an advanced type of power training specifically designed to harness the muscles’ and tendons’ ability to store and then rapidly release energy.

The most popular plyometric exercise is probably the depth jump to high jump. It involves stepping off a low platform or box, dropping vertically, absorbing the landing by flexing the hips and knees, and then immediately launching into a high jump, usually onto a box or over a hurdle.

Depth jump to high jump video demonstration

During the landing after the initial drop, as the energy of the landing is absorbed, the muscles are forced to eccentrically contract and stretch. The tendons, which attach the muscles to bones, stretch even more than do the muscles. Most of the gravitational energy that enters the muscles and tendons is lost as heat, while some of it is temporarily stored. In order to launch into an immediate jump, the muscles then concentrically contract. The force of the concentric contraction coupled with the energy that was stored within the muscles and tendons produces a more explosive movement than would have occurred if the initial eccentric contraction and stretch had not taken place.

Because the muscles and tendons stretch during the eccentric contraction and shorten during the concentric contraction, the whole process is known as the stretch-shortening cycle (SSC). The transition between the eccentric and concentric contractions is known as the amortization phase. In order for an exercise to be considered truly plyometric, the amortization phase must be extremely short, ideally taking no longer than 0.25 seconds. The reason is that, in exercises in which the amortization phase takes longer, the stored energy is dissipated as heat and the plyometric effect is lost. Although such exercises can be used to develop power and to prepare for plyometric exercises, they should not themselves be deemed plyometric.

What are the benefits of power and plyometric training?

Power and plyometric training can help you to:

  • Develop explosive power
  • Increase the height and length of your jump
  • Boost your running speed
  • Improve your coordination, balance, and agility
  • Enhance your reflexes and reaction times
  • Develop functional fitness and strength
  • Strengthen your muscles, bones, tendons, and ligaments
  • Reduce your risk of sporting injuries
  • Improve your overall athleticism and sporting performance