Can weighted plyometrics increase vertical jump?

As a physical therapist and strength coach, I often receive questions from coaches and athletes. Recently I was asked about weighted plyometrics.

Here is the question:

"I am coaching volleyball this year. What are your thoughts on weighted plyos to increase vertical jump? 10-11% body weight in form of vest.  I have found a lot of evidence in support…"

I wanted to share my thoughts on this question as this is something I get asked about a lot and I unfortunately see personal trainers, strength coaches and sports coaches inappropriately adding load to movements that they shouldn't be in the hopes of improving athletic performance.

Some initial questions I had were: How old are the kids? What is their training age (how long have they been training in a strength and conditioning program)? How do the kids move? Can they squat, deadlift and lunge with proper body mechanics? What about running and jumping?

Below is my initial response:

I think the main thing you want to think about is training age and not placing load on top of dysfunctional movement patterns. I think vests can be a great tool but only if the prerequisite body mechanics and ability to control load has been established prior to adding in dynamic activities. I have found that many athletes (even at the D-1 and professional levels) do not have this control which increases their risk of injury or this has led to their injury as they get older and their force production increases. Just because an athlete participates in a higher level of competition does not mean that they move well. This is why you see some athletes that are frequently injured and some that never seem to get hurt. In my opinion you will first want to teach the kids how to eccentrically control landings and jumping with good body mechanics and knee valgus control prior to adding the weight vest. You have to learn to brake the car before it can go fast. 

Especially in volleyball and basketball players where there is a high incidence of ACL injuries you want to make sure to that they can hip hinge and control the knee valgus moment. Improving posterior chain, hip and lower extremity strength while addressing trunk, hip, knee and ankle stability and neuromuscular control during both single leg and bilateral activities is key. These are all things that can be accomplished on a field or court with little to no equipment and a skilled coach can work on varying levels of athlete at the same time.

If your goal is to improve the athletes' vertical jump height this will improve just by improving form, overall body mechanics and subsequent force production through the ground. You will also be reducing their risk of injury at the same time.

As you see above there are a lot of prerequisite skills that need to be coached and mastered before haphazardly adding load to a movement. Running, jumping and loaded plyometrics are all high level skills that need a basic foundation before you can build into these exercises. The same goes for even the most foundation human movements that include squatting, hip hinging, push, pull, rotation and carrying. Make sure that you consult with a qualified professional before just jumping into a training program.

Jon Herting, PT, DPT, CSCS, USAW is a physical therapist and strength coach in Garnet Valley, PA who specializes in athletic rehab, reconditioning and return to sport.  He is a guest contributor for Sports Doc.

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