In the 1970’s Olympics Fred Wilt observed the Soviet exercise practices, and he found that they were jumping—a lot. He was witnessing the practice of programs developed by Russian scientist Yuri Verhoshansky. Wilt believed this practice of rapid-fire jumping led to Russia’s success in many running events that year. Later, Wilt teamed up with Russian trainer Michael Yessis to further develop and promote the practice, which he coined as “plyometrics” (more + measurement).
Initially, plyometrics referred to a distinct jumping exercise that was both explosive and powerful and emphasized an extremely fast recoil between each jump. Later, plyometrics blended with American “jump training” and lost some of its purity by incorporating regular jumps without the super fast recoil. These two forms of plyometrics—the pure and the American—are the topic of some controversy, however, both are good for exercise and wellness. The pure form remains a crucial staple in sprint training. Coupled with treadmill training this can be great to get through the winter.
Three Phases of Plyometrics
The pure plyometrics practice consists of three important phases that together form a cycle:
The eccentric phase is the landing phase. For example, in a basic squat jump, this phase would include the portion of the movement from when the feet touch the ground to the bottom of the squat. During this phase, elastic energy is stored and muscle spindles are stimulated.
The amortization phase is the transition phase or the bottom of the cycle. Continuing with the squat jump example, this phase includes only the portion of the movement at the bottom of the squat. This should be the shortest part of the cycle. It is the recoil between jumps. Professional sprinters bring this phase down to mere fractions of a second. For pure plyometric training, it is vital for this phase to be a short as possible. If the amortization phase lasts too long, the energy stored in the eccentric phase dwindles and the plyometric effect is lost.
The concentric is the actual jump phase. This phase includes the portion of a squat jump from the bottom of the squat, to the peak of the jump, and back down to when the feet touch the ground. In this phase, the energy stored in the eccentric phase is used as explosive power to reach the highest maximum height.
Experiment with Depth Jumps
- Stand on top of a box that’s approximately knee high with feet shoulder-width apart and toes near the edge of the box.
- Step off and land in a full squat position. This is the eccentric phase.
- Spend as little time on the floor as possible. This is the amortization phase.
- Jump as high as possible off the ground. This is the concentric phase.
Depth jumps are a great way to apply some of the basics of plyometrics, but don’t stop there; try some of the many other plyometric exercises out there. Your running game will thank you. Plyometrics quickly builds leg muscles in a way that will also increase agility and sprinting speed.