Tip of the Month - April 2026
Training with Plyometric Exercises
The Tip of the Month is a supplement to the April News article on implementing plyometric training in programs for developmental athletes. I think it is important to understand the background and concepts involved in this training method.
The Background – What is it?
The term “plyometric” is a combination of Greek root words: “Plyo” from “plythein,” meaning to “increase,” and “metric” literally means to “measure.” Definition: Exercises in which muscles are repeatedly and rapidly stretched (loaded) and then contracted (for example, jumping off the ground or a push-up with a hand clap in the air. These exercises are quick, powerful movements that involve pre-stretching the muscle, thereby activating the stretch-shortening cycle. The aim is to improve muscle power. USA Track coach Fred Wilt (1920-1994), an American runner and later an FBI agent, first coined the word after watching Soviet athletes prepare for their events. He competed in the 10,000m at the 1948 and 1952 Olympics, finishing 11th and 21st, respectively. After retiring from the FBI, he became the head coach for the women’s Cross Country and Track and Field teams at Purdue University and wrote “Soviet Theory, Technique, and Training for Running and Hurdling.”
The Training Concept
Soviet Olympians had initially used the plyometric method in the 1950s, which was then adopted worldwide. Wilt began collaborating with Soviet trainer Michael Yessis promoted the technique, which included explosive exercises to activate the quick-response and elastic properties of the major muscles. These are known as ‘jump training’ or ‘plyos,’ in which muscles exert maximum force in short intervals to increase power (speed-strength). The training focuses on learning to move from muscle extension to muscle contraction in a rapid or ‘explosive’ manner, such as in specialized repeated jumping. The science underlying this method is based on findings that muscles respond exceptionally well to rapid alternation between lengthening and shortening while resistance is continuously applied. Whereas this training method is used to develop explosive power, it must be implemented cautiously.
Three-way Muscle Contraction
It is essential to understand the workings of muscle contraction. Muscles contract in one of three ways:
Concentric contraction - when the muscle contracts and shortens at the same time
Example: Chin-up position The biceps muscle (upper arm) contracts and shortens as the body is raised up to the chin-up bar or when performing a biceps curl
Eccentric contraction - the muscle contracts and lengthens at the same time – the total length of the muscle increases as tension is produced
Example: Lowering the body from the Chin-up bar The biceps muscle (upper arm) contracts and lengthens as the body is lowered. Muscles are capable of generating greater forces under eccentric conditions than under either isometric or concentric contractions
Isometric contractions - the muscle contracts but does not change in length – it is a muscle contraction without motion
Example: Hanging from the Chin-up bar – Arms bent at 90° It is used to stabilize a joint, such as holding a weight at waist level, neither rraising or lowering it. The biceps muscle (upper arm) contracts but does not change in length because the body is not moving up or down.
Basic Physiology
The process involves the so-called ‘myotactic reflex mechanism’ (cycle: stretch- shortening). The muscle is eccentrically loaded and immediately followed by a concentric contraction of the same muscle or muscle group (amortization period). Depending on the movement and the application of force, specific angles are more favorable for optimal explosive power. Therefore, exercises must be carefully selected to achieve the desired effect.