A growing number of CrossFit coaches are programming only “jump up-step down” box jumps in their training sessions. Why? Achilles tendon tears happen way too often in high-rep box jump sessions, making it one of more dangerous exercises in CrossFit – especially if you are a guy. The male to female ratio for Achilles tendon rupture varies between 7:1 and 4:1 across various studies.

Step down vs. Jump down

CrossFit Snohomish covers the basics of the jump up-step down box jump:

The jump up-jump down method in my opinion should really be reserved for those looking to be competitive in the sport of CrossFit and even at that, should possibly be saved for game day performances.

This method trains the explosive component of the movement that is the hallmark of the box jump. While providing the power and coordination of the jump, it also minimizes the risk on the descent back to the ground. It lacks some of the coordination and agility of our final option, the super speedy jump up-jump down version of the movement. This type of box jump is by far the fastest and I believe has the most potential to train the physical abilities that we are shooting for on the box jumps. It also has the most inherent risk due to the potential to get out of control and due to the rapid and forceful stretch/contract sequence in the calves and Achilles during the quick bounce off the ground.

And what method do they recommend for their clients?

I believe that the jump up-step down provides the most training effect while minimizing risk. The jump up-jump down method in my opinion should really be reserved for those looking to be competitive in the sport of CrossFit and even at that, should possibly be saved for game day performances.

…Most of these [injuries] are probably occurring at the point at the bottom of the jump down when the tendon becomes the most stretched and then is forced to contract for the next jump.

How did I come to this opinion? First, I have seen enough people struggle with the coordination of the jump up-jump down method and rake shins, twist ankles, hurt knees (me) etc… This is why I originally did not allow them at all. After our recent box jump injury, I have been doing my own informal research and have heard of enough other athletes getting the same torn Achilles injury that I am beginning to feel there is a connection between the jump down method and this particular injury. I believe that most of these are probably occurring at the point at the bottom of the jump down when the tendon becomes the most stretched and then is forced to contract for the next jump.

Box jumps for time?

For a more personal (and salty) account of what high-rep box jumps can do, read Sexyasfuck’s account of his Achilles tendon blowout and how it turned him away from pure “unknown/unknowable” anything-goes programming:

How many blogs do you have to read until you realize how fucking retarded box jumps for time are?  The answer should be one. This one. Or any of the 50 other blogs containing detailed accounts of people exploding their fucking Achilles tendons whilst doing high rep box jumps. …

Your shoulders and Achilles are nothing but ticking time bombs.

Let’s just be smart about what we do “for time.” Box jumps by themselves are fucking awesome. There is almost no better way of building speed and power. But as soon as you turn them into a contest, retards like me start doing them touch and go. No “time” or “trophy” or position on a podium is worth what happened to me.  Same goes for kipping pullups. Angie is an awesome test of how awesome you are. But performing 100 kipping pullups in short order will surely fuck up your shoulders. If you are lucky enough to not have suffered shoulder pain from high rep kipping pullups you are one of the lucky ones. Your shoulders and Achilles are nothing but ticking time bombs. I’m still going to perform Angie, Fran, and the others. But not with kipping.  I will still get the cardio benefit, I am sure of that. I might never jump off a box ever again, however. I have awoken twice from nightmares of my Achilles blowing up. Like a mild form of PTSD or something.

Still not convinced? Google “box jumps torn achilles” like he mentions and take a spin through the reams of accounts, a number of which occurred after the 2011 CrossFit Games Open 11.2, an AMRAP that included 15 box jumps using a 24″ box.

Love your Achilles and step off the box!