Plyometric exercises can be incredibly valuable tools in performance enhancement. Powerful, dynamic movements are the hallmark of most sports, and adding inches to a vertical jump or slightly enhancing ground reaction time is golden when we look at productive programming. That being said, plyometrics are also commonly misunderstood, misused and sometimes even unsafe in many athletic programs. So before I get into (proper) plyometric programming, I'll offer a little background as to exactly what they are.
Plyometrics = Power Training
Plyometrics are a form of power enhancement. They are not intended to enhance body composition. Often misused as forms of "cardio," they have little or no place in programs that are not focused on dynamic athletic ability. They are simply meant to enhance the athlete's ability to produce maximum force in a given instant. To do this, they tap into an involuntary "reflexive" contraction that occurs during the stretch-shortening cycle when athletes change direction.
The countermovements in plyometrics stretch the muscle rapidly, and the body reacts by contracting the muscle involuntarily, adding power to the contraction. This comes in handy during stopping and starting motions, when the athlete needs to rapidly absorb and generate maximum force in less than 0.5 seconds. Quickly changing direction and jumping to one's maximum vertical height are the primary goals of most plyometric programs, and limiting the time between the stop and start of such movements (we call this the "amortization phase") is the specific task of plyometric movements.
You can see how plyometrics can be valuable to athletes who have already developed a solid base of strength and coordinated movements—which leads me to the whole area of "pre-plyometric" programming.
Developing a solid strength base and level of athletic ability is important not only for safety reasons, but also to make plyometric training effective. If we introduce plyos to athletes who lack a solid foundation of strength and base skill sets, we set them up for higher risk of injury—and we may also be wasting their time. The NSCA recommends that, for safety purposes, you should be able to squat 1.5 times your body weight before performing intense plyometric training. But many trainers and coaches fail to assess whether plyometric movements are really a productive means to enhance an athlete's power production, especially if the athlete has not prioritized basic strength training and sport-specific practice.
First off, be sure your athletes have prioritized strength training and sport-specific skill acquisition before working plyometric training into their programs. They offer more return on time invested than plyometric training, and they increase the effectiveness of plyometric drills. Once an athlete has developed lower-body strength—at least to the point where he or she can squat the recommended amount—plyometric training can enhance his or her quickness and power in dynamic scenarios.
When programming plyometrics, treat it as you would a skill acquisition drill. After all, power training is very similar (if not exactly like) skill training. We work to optimize form and timing so we translate as much force as possible, as precisely as possible, into the given movement pattern. An inefficiently timed drill, or one in which form is not optimal, will lose energy the athlete expends.
I've included a few guidelines that I use in plyometric training. Admittedly, they reflect my own subjective interpretation of what constitutes a sound plyometric program. Intensity, duration, and frequency change based on the athlete and the specific program, but these guidelines hold up no matter your athlete or the sport they play.
Assign plyometrics when the athlete is fresh and warmed up.
To optimize form and skill acquisition, the athlete should be in a non-fatigued state (relatively speaking). Ever try to teach free throws to a basketball player after a long practice? You can imagine how frustrating that might be. And since improving at plyometrics involves improving the technical points (form and timing), the best part of practice to implement plyometric drills comes at the beginning of the routine.
Keep the sets non-fatiguing to maximize effectiveness and safety.
More intense plyometric movements, like depth jumps, are inherently high-risk. When they are done until fatigue, the athlete not only loses the mechanics and timing needed to make the exercise effective, he or she also increases the chances of an adverse event, like a torn meniscus, hyperextension, muscle strain or joint sprain. In my book, an injury from plyometrics during training is unforgiveable—and I guarantee the athlete's parents will feel the same way.
Focus on whole-body form, not jump height.
I've probably beaten this one to death, but with good reason. Improper plyometrics will not improve the athlete's abilities. It really is that simple. Focus on form, form, form, and leave the bragging about "40-inch hops" to the athlete after he or she has left the room. A solid coach does not care about the end result as much as what got the athlete there to begin with. Focus on arm swing, angles of knee and hip flexion, torso alignment and timing of all of the above. The fine points of technique are what will get the athlete hitting the backboard.
Work to decrease time the athlete spends in the amortization phase (the time between eccentric and concentric movement).
Once the preceding points are taken care of, you can focus on limiting the amount of time the athlete spends on the ground. The longer you spend changing direction, the less potential you have to gain power from the involuntary contraction elicited during the stretch-shortening cycle. This is why plyometric abdominal drills are outdated—the proximity of the abs to the spinal cord is such that we can't react soon enough to get any real contribution through an autonomic response. The legs, however, can muster a ton of force from this reflexive action—if we keep the amortization phase short enough. Spend too long transitioning from down to up, and that precious energy will dissipate, leaving us with less contractile force moving in to the leap, bound or throw.
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