-No strength coach, ever.
You see, jumping, commonly referred to as plyo's, or plyometrics (when actually done, as a plyometric...more on that later), is frequently over-used and misunderstood.
Prescribing jumping for runners? Who take 750-800 small, low level jumps per mile? Runners don't need to learn how to jump. They need to learn how to LAND. Force absorbtion, in this case, trumps force application. And when more injuries happen to marathon runners than powerlifters, olympic lifters and weight trainees combined? It's time to re-think the use of jumping within each training session. Should you REALLY add jumping to your program?
Here at Structure, we RARELY use jumping/plyometrics. And it's time we explained why.
Plyometrics have deep roots in Europe, when coaches such as Fred Wilt, Michael Yessis and Yuri Verkhoshansky were prescribing depth jumps, box jumps, hurdles, and loaded jumping back in the 1960's and early 1970's.
But what exactly IS a plyometric?
Technically, the term refers to the highly demanding shock method first coined when athletes would jump off of a platform/box of sufficient elevation and land, thus sending a shock into the muscles. Upon landing, the athlete would immediately takeoff. IMPORTANT: time spent on the ground should be between 0.1-0.2s, otherwise the SSC, or Stretch shortening cycle will NOT occur.
Ah, Coach, another fancy term? Stretch WHAT?
Stretch shortening cycle (SSC), happens when muscle lengthens, (as in bottom of depth jump as you sink into a squat and your hamstring and quad muscles lengthen). As a result, the force applied to the muscle increases, and hopefully, if strong enough, the quad, hamstring and glute muscles concentrically contract to shorten and use the stored energy to increase the contraction force.
In short, the SSC is another name that symbolizes a muscles contractile ability, similar to that of an elastic band. A quick pull on that elastic band will yield a very powerful attempt to return to its resting length. More force on that band (higher height) will increase the force upon both the band and the potential for it to snap back (jump higher).
To get REAL technical, let's break the actual movement down even further into four distinct phases:
- Momentum phase: body is moving because of kinetic energy accumulated from preceding action (dropping from a height)
- Contact instant: contact with a surface prevents the body or part of body from moving further
- Amortisation phase: when kinetic energy produces a powerful stretch reflex; leads to eccentric muscle contraction accompanied by explosive isometric contraction
- Rebound phase: involves release of elastic energy from tendons and other tissues together with the involuntary concentric muscle contraction evoked by stretch reflex
GOAL of Plyometrics?
With traditional strength training, the mass (weight) lifted is increased, and as a result, static strength and hypertrophy are increased. With plyometrics, the goal is strictly to shock the muscles into an involuntary, neuromuscular and CNS (central nervous system) process.
The muscles are being taught to respond quicker than ever before.
Types of plyometrics will be discussed in our next post.
- Dr. Michael Yessis (2009). Explosive Plyometrics. Ultimate Athlete Concepts.
- Yessis, Michael. "Why is plyometrics so misunderstood and misapplied?". doctoryessis.com. 30 April 2013.
- Wilt, Fred & Yessis, Michael. Soviet Theory, Technique and Training for Running and Hurdling. Vol 1. Championship Books, 1984.
- Dr. Yuri Verkhoshansky, Natalia Verkhoshansky (2011). Specialized Strength and Conditioning, Manual For Coaches.
- Zatsiorsky, Vladimir & Kraemer, William. Science and Practice Of Strength Training. Human Kinetics, 2006.