We’ve seen athletes showing off their crazy-high Box Jumps on Instagram. At first glance, they are jaw-dropping feats of athleticism. A guy like J.J. Watt, who’s listed as 288 pounds, jumps up to a 61-inch box. That’s over 5 feet! Really?

But if you look at what’s actually going on, such jumps are not quite as impressive as you might think.

Watch Watt closely in the video below. He jumps up, tucking his knees to his chest so his feet land on the box, barely (he actually fell back on his trainer in a previous attempt).

Watt isn’t actually jumping over five feet. He’s using momentum and technique to simply get himself up onto the box. Look at his hip level in the screenshots of his jump, below. They show you how high his body actually traveled.

Let’s assume that since Watt is 6-foot-5, his hips are about 3-foot-3 inches off the ground when he’s standing. At the peak of the jump, his hips appear to be at about 1 foot above the box, which equates to 6-foot-1-inch above the ground. That means his total jump was a little under 3 feet. That’s impressive in its own right, but it’s not 5 feet. The other 2 feet are gained from his knee tuck.

According to elite strength coach Mike Boyle, co-founder of Mike Boyle Strength and Conditioning, when you land on a box, you should be in the exact same position as when you started the jump—knees and hips bent in a quarter-squat stance—not in a crunched-up ball like what you need to make a max jump like this.

The Box Jump pictured below shows it’s possible to have a high Box Jump without using an absurdly tall box. This jump begins just like Watt’s, but the finish is executed with proper technique.

This jump is nowhere near the height of Watt’s jump, but it demonstrates that it’s possible to actually jump high without an oversized box. Notice the hip height over the box at the top of the jump.

It may not be as flashy, but doing it like this has benefits. First, you use max power to jump up and land in the quarter-squat position. If you use a box too high, you might actually sacrifice some power, because you’re so focused on tucking your knees up and not driving fully off the ground. Second, landing in the quarter-squat stance is safe. You won’t be in as great a risk of missing the jump as you would be by attempting a max jump. Even great athletes like Watt can miss a rep, which he showed can happen. It’s always better to be safe than sorry, because an injury simply isn’t worth it.

Now, we are not dissing or discrediting Watt’s athleticism. The guy is an absolute beast. But we’d like to see him show off using safer and more realistic tests like a Vertical Jump or a Broad Jump. There’s a reason these exercises are used as tests in the NFL Combine. The Box Jump is a fantastic exercise for developing explosive power, but it shouldn’t be used with a box height that does not allow you to do it right.