The Background
Okay, if you’re reading this you can probably see some irony in the title of the article already. Of course, I intend this short review to point the flaws in many other internet tutorials about Plyo’s, so there’s a point to the title. The issue is simple, too many sites show you fancy jumping, bounding and hopping exercises, but they don’t tell you how to actually make them Plyomeytrics instead of plain old jumps, bounds and hops.
Take for example this video from Expert Village, purporting to show us some Plyo’s. I see some really fast step-ups, good speed training. Then we are shown a Medicine Ball Squat Toss (MBST), performed repeatedly at low intensity - so we’re getting a bit of strength and endurance training. No Plyometrics. “But”, you say. Hold it there, I know what you’re thinking. The MBST can be performed in a way that makes it Plyometric. The video does not demonstrate this.
The Science
To understand the flaw in the video, and in many other descriptions on the internet, we need to know what makes Plyometrics, Plyometrics.
Stretch-Shortening Cycle (SSC)
An SSC is the performance of a rapid concentric (shortening) contraction following an eccentric contraction (muscle lengthening while producing force) 1. We see in the video of the squat, the trainer squats down, performing the eccentric stretch phase, then stands up, demonstrating the concentric phase. As demonstrated many times, correctly performed SSCs produce more power in a shorter amount of time than regular concentric contraction 1.
Many researchers see the SSC as being beneficial because it promotes a build-up of elastic energy in the musculotendinous unit, then a rapid release of this energy that results in greater power output 2. A further effect of a correct SSC is reported to be the inducement of stretch reflex activity during the concentric phase, again enhancing power output and explosiveness 3.
Amortisation Phase
This is where the video above falls down (no pun intended). For the elastic energy to be utilised (rather than dissipate) and the reflex activity to be induced, the SSC must be performed very rapidly. In particular, the switch between the eccentric and concentric phases must be absolutely minimal 4. The time between the two phases is called the Amortisation phase. This leaves Plyometric exercises with three main aspects:
- Eccentric stretch phase
- Amortisation phase
- Concentric contraction
The Internet
What the articles and web pages I see on the internet lack is an appropriate Amortisation (Amortization if you’re American) phase. Our guide in the video was not nearly dynamic enough. By the time she started the upward part of the squat some of the elastic energy in her muscles and tendons would have dissipated. It was a regular squat.
Now that you know the difference between a Plyometric exercise and a normal strength exercise, see if you can pick the ones below. I hope reading this made sense and wasn’t toooo full of jargon. Please post a comment if something didn’t make sense.
Simple Plyometrics Workout - Youtube
How to Practice Jumping: Plyometrics Drill 2
Sport Fitness Advisor
Ghetto Jump Training - Embedded Youtube
1. Miyaguchi, K., & Demura, S. (2008). Relationships between stretch-shortening cycle performance and maximum muscle strength. Journal of Strength and Conditioning Research, 22, 19-24.
2. Winchester, J., Nelson, A., Landin, D., Young, M., & Schexneyder, I. (2008). Static stretching impairs sprint performance in collegiate track and field athletes. Journal of Strength and Conditioning Research, 22, 13-18.
3. Bosco, C., & Komi, P. (1982) as Cited in Winchester et al. (2008).
4. Dodd, D., & Alvar, B. (2007). Analysis of acute explosive training modalities to improve lower-body power in baseball players. Journal of Strength and Conditioning Research, 21, 1177-1182.
How to do Plyometrics Properly by Matt Vickers is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported License.
