Box Jumps: You’re doing them WRONG!
I often contend in this space that there are no bad exercises, just exercises that are used inappropriately. That is, you have to decide if an exercise will help you reach your fitness goals. So to help you decide that, there are two goals that box jumps will help you reach:
1. Post-Activation Potentiation. In simple terms, muscle contraction is strongly influenced by its immediate contractile history. In other words, a series of powerful contractions will prime the muscle chemically and neurologically to contract powerfully for several minutes afterward and possibly longer term if the athlete adapts. A set or two of explosive box jumps may enhance the performance of subsequent sets of deadlifts, squats, cleans, and so on...in theory.
2. Safely Training to Increase Vertical Jump. Using a box to jump on while practicing your vertical jump spares the connective tissues and joints that might otherwise be pounded into hash by simply jumping and crashing to the ground.
Notice that I did not list “being different” as one of the goals. In terms of human physiology, we are all more or less the same, yes, even you, Snowflake. If you want to express your individuality, do it with your hairstyle, not your workout.
In no particular order, here are some of the biggest mistakes I see people making while doing box jumps.
Using Box Jumps for Metabolic Conditioning: Using box jumps for MetCon might be the leading reason for injury on this particular implement. If you’re using box jumps for PAP, doing box jumps to the point of fatigue will defeat the purpose. If you’re doing box jumps to work on your vert, what’s the point of doing them to exhaustion? That can only lead to injury—possibly season-ending injury. There are dozens upon dozens of better ways to work on your conditioning.
Jumping Backward off the Box: Is backwards to the goal of preventing injury by using box jumps to alleviate the stress on your body while vert training, and it boils down to just plain laziness. Either jump forward off the box and turn around to jump back up or step down off the box one leg at a time. Simply jumping backward off the box subjects the Achilles tendon to a tremendous amount of shear force, up to 1,800 pounds for a person weighing 150 pounds. Then it only gets worse if you contract the calf during this violent stretch in preparation to jump again. It won’t take many reps of this to spur some tendinopathy and even a rupture of that tendon. If you ever get a full-thickness rupture of your Achilles tendon, you are looking at the better part of a year spent on recovery and rehab before you can even BEGIN training again. Do them correctly, or don’t do them at all.
Using Too High of a Box: This is without a doubt the worst mistake. If you understand the purpose of a box jump, you understand that the goal is not to jump on the highest box possible. Look at people landing on an ultra-high box jump. They land with their knees up around their ears, back rounded, and head down. They are in total flexion. If you ended up in that position on the playing field or court, you would get your head handed to you. Now look at a photo of Michael Jordan on a layup. He is in complete extension, spine, hips, knees, ankles, all in full extension. Flexion is the enemy of a good vert. Do you want a vert like Mike, or the vert of a troll living under a bridge? Unless you are a seven-feet tall pro-baller, you don’t need any more than a 30” box—max. Using too high of a box will also lead to undesirable compensations to get the flexion needed. Buckling knees and over-pronated feet are the opposite of how an athlete moves.
Yes, a ridiculously high box jump may look impressive, but winning at your sport is better.