In the majority of cases, the Depth Jump is the greatest exercise you can perform to improve your vertical jump. It is also one of the best ways to increase reactive and explosive power in a variety of other athletic movements.
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A major problem relating to this exercise, however, is that many coaches lack a thorough understanding of how to properly manipulate box height for maximal performance gains.
Copying the box height and Depth Jump technique of a video on the internet is not a good basis for the performance and progression of this powerful exercise.
Whether you are aiming to build a huge standing vertical jump or are just seeking to develop better landing and push-off mechanics, knowing how to set the height of the box for depth jumping to meet your exact needs will help you accomplish your athletic goals, and then some.
Three major factors should impact the height of the box chosen for a Depth Jump: chronological age and training age; plyometric ability level; and training focus, power versus reactivity.
Chronological Age and Training Age
The first thing you or your coach needs to do is assess your age and training-based readiness. Young athletes and those who are inexperienced in plyometrics should choose lower boxes, but you don't need to go overboard on this idea. I've lined up a group of youth athletes (ages 8-14) of varying ability on a 16-inch park bench; and after 15 minutes of instruction, everyone was landing and depth jumping with good mechanics and power. Watch kids at the playground, and you'll see landing forces that often exceed what we would traditionally "prescribe" for them in a training environment years later.
There are two optimal windows for youth athlete speed and power development that coaches and parents should be aware of. For boys, those windows are purported to be at ages 7-9 and ages 13-16. For girls, the first window is at ages 6-8 and the second at ages 11-13. I'm not advocating Depth Jumps for the younger groups—kids achieve that from regular play—but in that second window, there can and should be some form of introduction to the high-speed, high-force qualities of Depth Jumping.
Although some may argue against "early intensification" with the Depth Jump, the nature of that intensity is completely driven by the height of the box. Although there is no "science-based" long-view study on this, I generally recommend that even the best youth plyometric athletes under age 14 stick with boxes no higher than 18 inches, and athletes under 18 go no higher than a 30-inch height—or perhaps 36-inches for higher-level male track & field competitors. Girls and boys under age 14 can have the same box height in most cases. Girls 14-18 will generally want to stick with box heights under 24 inches.
Along those same lines of "early intensification," I would argue that a basic ability in single-response plyometrics (Depth Jump) is important for youth athletes, in light of the windows of neurological programming we just discussed.
Although training age is very important in how intense to make the Depth Jump, plyometric ability is even more of a determining factor. An athlete who has spent years in the weight room, yet can't pop off the ground in a Hurdle Hop reflexively, has big limitations on the height of the box for Depth Jumping.
An easy way to determine an athlete's plyometric ability is via the following test series:
- Measure an athlete's standing Vertical Jump.
- Have the athlete perform a Depth Jump from a 12-inch box and measure the Vertical Jump in his/her reaction.
- Increase the box height by 6 inches, and measure the reaction Vertical Jump height again.
- Keep repeating this process until the athlete can no longer come within 1 inch of the Standing Vertical Jump.
Athletes who cannot come within 1 inch of their jump from a 12- to 18-inch box have poor reactive ability. Those who can have average ability, and those who can match, or come within 1 inch from a 24-plus-inch box have good reactive ability.
For general Depth Jump performance, use a box that is close to the point in the above test where the athlete's reaction jump starts to drop off. For example, if an athlete can no longer come within 1 inch of his/her best standing Vertical Jump from a box set at 36 inches, then 24 to 30 inches would be a good box height to work with, yielding a good plyometric overload. Only using a 12- to 18-inch box wouldn't challenge the athlete enough.
Training Focus: Power or Reactivity
Athletes training for raw power will generally use lower boxes, while athletes aiming for reactivity will choose higher boxes. See the two videos below for a good explanation. The first is a football player with more strength, and the second is a high jumper with more reactive power.
What's the difference between jumping for power and jumping to reaction? Think of it this way: power Depth Jumps (the football video) have more transfer to things like the following:
- Short acceleration
- Vertical jumping from a standing position
- Powerful contact moves in the post or on the line of scrimmage
- Other powerful bursts where the legs bend and you use lots of muscle power to push
When you think of power, think of a muscular, running back-type athlete. Reactive strength, on the other hand, is strength that uses relatively straight legs, and the power of the muscle-tendon complex to spring an athlete across the field, or through the air. Reactivity refers to skills like the following:
- A quick change of direction when running at speed
- Jumping from a running start
- Top speed sprinting and bounding
- Jumping in a quick manner to block a shot or make a flying catch.
When you think of reactive strength, think of a long, lanky "dunk from the free-throw line"-type of athlete like Zach LaVine. Generally speaking, athletes who have natural qualities in power do better by jumping from lower boxes (12-24 inches), while athletes with natural reactive strength do better from higher boxes (24-48 inches).
Even within the scope of an athlete's natural preference or ability for a particular box height, you can adjust the box height depending on the direction the athlete wants to push his or her training. A power athlete who wishes to become more reactive should aim toward the higher end of his or her best tolerated drop height. A reactive athlete who wants more power and muscular strength in his or her jump will do well to choose a lower box height than what he or she can tolerate and aim for an overhead target at the end of the Jump, such as shown in the video below.
Photo Credit: Getty Images // Thinkstock