|Strength & Conditioning for Lacrosse: Plyometrics (Power Training)|
By Billy J. Voltaire, CSCS
Like most sports, lacrosse requires you to have adequate strength, muscular endurance, speed, and power. The term power in lay conversation is one that is often used interchangeably with strength. However, the two concepts are completely different, yet work in tandem.
Strength vs. Power
By definition, strength is the maximal amount of force generated in one effort. Power is calculated based on the amount of force you can generate and how fast or explosive you are able to produce that force. The two work hand and hand. Without improving strength, it is difficult to improve your explosive abilities or be “powerful.” Strength is usually measured by your 1RM (one-repetition max) and determines how strong you are.
Power can be determined based on your vertical jump, broad jump, or medicine ball chest pass. Power training is an integral part of any strength and conditioning program, especially when your goal is to improve speed and agility. Plyometric training has also been proven to significantly decrease the likelihood of injury in female athletes.
Plyometrics is a mode of training that uses the body's basic reflex (myotatic reflex) to produce fast and explosive movements. Every time we run, jump or hop, we are doing some sort of plyometric movement. Plyometric training is only effective when done efficiently, which requires you to be fast and explosive. There are several different subcategories of power: starting power, accelerative power, and power endurance, to name a few. Each position on the field has different demands, and training should be specific and tailored to these demands.
Starting power is simply the ability to explode from a resting or starting position, as done in a face-off, for example. Accelerative power is the ability to be continuously explosive with each stride as you sprint down field. Power endurance, as the name suggests, is the ability to maintain optimal power production over a long period of time while being resistant to fatigue (e.g., the work of a midfielder).
Explanation and Examples
The foundation to plyometrics is the stretch-shortening cycle. As mentioned in the Romanian Deadlift article, eccentric contractions occur when a given joint is rapidly stretched and, as a protective mechanism, our body contracts to slow down the movement. During this quick stretch, the body reflexively counteracts this movement by producing a concentric contraction to prevent further stretching. Plyometric training focuses on using this reflex to facilitate an even more explosive movement.
An example to best illustrate this point is in basketball: When jumping for a rebound, most if not all athletes quickly squat down (quick stretching of the gluteus maximus and quadriceps) and without hesitation jump (shortening) as high as they can. Another example is in shooting for lacrosse: The offensive player almost always “winds up” (stretching) by quickly bringing the stick to the opposite side of the body followed by an explosive rapid movement (shortening). Without this pre-stretch, the power output our body produces would be significantly less. Think of jumping from a standstill versus jumping with this pre-stretch.
The period between the quick stretch (eccentric contraction) and the explosive movement (concentric contraction) is called the amortization phase. Each of these three phases build off of the preceding phase and require coordination, balance, and speed. If the pre-stretch is not fast enough, or the amortization phase is too long, or the movement is not explosive enough, we gain little to no benefit from the repetition.
The following guidelines should be considered when incorporating plyometrics into your strength or speed training program.
Note: Plyometric training is not recommended for prepubescent athletes because of the stress placed on the joints and its risk of premature closure of the growth plates.
* medicine ball
Terms to Know
Amortization: Period between eccentric and concentric contraction. Emphasis must be placed on getting off the ground as quickly as possible to limit time spent in this phase. Too much time in amortization is wasted elastic energy and loss of power!
The science and application of plyometrics goes well beyond what has been discussed in this article. For more information, feel free to contact me or refer to the following references:
Hewett, Timothy E., Stroupe, A., Thomas, N., & Noyes, F. (1996, December). [Review of Plyometric Training in Female Athletes Decreased Impact Forces and Increased Hamstring Torques.] American Journal of Sports Medicine, 24(6), 765-773.
Previous Strength & Conditioning for Lacrosse Articles
Billy J. Voltaire, CSCS, is the Head Strength and Conditioning Coach at Manhasset High School in Manhasset, New York. He can be reached at email@example.com.