We examined the ups—and the downs—of the internet’s favorite exercise.
You can trace the current box jump craze to JJ Watt, the six-foot five, 290-pound defensive end for the Houston Texans NFL team. Just five days before the 2011 NFL draft, where he was taken as the 11th overall pick, he appeared in a YouTube video where, from a standing position, he launched himself onto a 55-inch tower of exercise boxes. "This is what a first-round pick is made of right here," says his coach in the video.
Two years later, Watt went bigger, starring in another, grainier cell phone video where he jumps from ground level to the top of a 59.5-inch box. The two videos have racked up nearly five-million views, and the latter was shown to the masses when Watt appeared as a guest on Jimmy Kimmel Live. Before that segment ended, the corn-fed football hero had jumped over Kimmel and his sidekick Guillermo.
Since then, hundreds of thousands of people have uploaded videos of their own box jump feats to Instagram. Each is mostly the same: The jumper stands in front of a tall box, raises his or her arms in the air, pushes back at the hips and slightly bends at the knees, swinging their arms back to their sides. Then the person explodes vertically, in mid-air lifting their feet onto the box to stick the landing.
Jumping, of course, is a fundamental human movement pattern, one that has long been a part of sport, whether it's the high jump event in the Olympics or simply a means of grabbing a rebound on an NBA court. As an exercise, it's a staple of athletic fitness programs—applying force against the ground to propel your body through the air requires nearly all your muscles to fire in synchronicity. But the #boxjumps phenomenon lies outside both sport and fitness, in an odd intersection between physical parlor trick and a need for "likes."
"Using too high of a box isn't getting you to a fitness goal," says Mike T. Nelson, an adjunct professor at the American College of Sports Medicine. That's because, he points out, no jumper ever launches himself as high as advertised. Nelson explains that the vast majority of people can't jump more than 35 inches off the ground from a standing position. The remaining distance is made up by pulling your legs up to reach the top of the box, causing you to land in a deep squat position. The highest standing vertical jump performance at the 2017 NBA Draft Combine, for comparison's sake, was 36 inches. For that player to do a 55-inch box jump, he'd have to clear another 19 inches with his legs. The latter half of the trick is actually more of a test of hip mobility than athleticism, Nelson says.
The landing is also troublesome. "If you saw someone land from a regular vertical jump in a full squat, with their knees up by their ears, you'd probably think, 'oh, that looks ugly, it doesn't look like a good position to land from a jump,'" says Doug Kechijian, co-owner of Resilient PT Performance, in New York City. "You don't ever see anyone land like that on a field or court—so the move just doesn't have a lot of application to sport or general fitness."
That slouched, squatted landing can also send a lot of stress to the low back, potentially causing injury, Kechijian says. And while the landing causes significantly less stress than Watt's back likely receives in an NFL game, the exercise may be something that Watt may want to avoid, considering he's had multiple back surgeries. Injuries could also stem from flubbing a high jump.
Jumping onto an appropriate size box, on the other hand, is a decent exercise because it helps you build power while removing the phase where you fall back to earth and have to land, which can be risky for less fit people, says Nelson. An ideal box height for a person who exercises every now and then, he says, is about 18 to 24 inches, or the height of a workout bench. Jump, snap your hips forward, and land in an athletic position with your knees just slightly bent.
But be aware that power is a fitness attribute that declines quickly, so the quality of your jumps is more important than their quantity: Two to four sets of about five well-intentioned jumps at the beginning of your workout is ideal. Do too many when you're fatigued and you won't see much benefit, and "you're also increasing your risk of injury—your knees take the biggest pounding, but there's also tendinosis, hip stuff, weird ankle stuff, and there's even a bunch of literature (that links box jumps to) Achilles ruptures," Nelson says.
You might be familiar with the exercise by way of CrossFit. The named workout "Kelly," for example, requires that you do a total of 150 24-inch box jumps—along with 150 wall ball shots and 2,000-meters of running—as fast as possible. "That's super advanced," says Nelson. "I don't ever have people do a high volume of box jumps, unless I know they're going to be competing in CrossFit, where they need to do that in their sport."
A recent CrossFit Open competition workout included a relatively high number of box jumps, and some of the videos got ugly. This isn't to criticize CrossFit—that workout was done as competition, and there are many sports, like football, that are far more dangerous. But it's worth noting that many of the method's workouts are rather advanced, which is why less advanced people might consider scaling them back.
It's also important to note that box jumps aren't the only way to jump. They're actually somewhere on the low to middle-end of the spectrum of athletic training. Once you've built up some fitness, falling through the air, absorbing the landing, then immediately reapplying force is a key component of building athleticism. "It's really what sports is all about," Kechijian says.
Consider the job of an NFL receiver or NBA forward. In a game, players don't jump onto something then pause and step down. A player sprints, launches himself in the air to grab a pass or rebound, falls to earth, then immediately sprints upfield or jumps again for a putback.
This process of absorbing force then immediately reapplying it to rocket your body forward or skyward is what scientists call the "stretch shortening cycle." In it, your muscles take on a "springy" effect, and it can cause you to jump higher than you would have if you were jumping from a standing position, according to a study in the journal Medicine and Science in Sports and Exercise.
"That's why you want to progress to where you're doing exercises where you fall from a height, land with a lot of stiffness, spend very little time on the ground, then automatically reverse and jump back in the air," Kechijian says. In practice, he has clients do exercise where they step off a low box, pretend the ground is on fire and rapidly jump up onto a higher box. Like all jumps, quality rules: Do a few sets of around five jumps.
So is there any benefit to the overly-high box jump? Of course: likes. A ridiculous box jump can create buzz around a budding athlete, or build the brand of a fitness influencer, eventually leading to monetization.
Watt, you could argue, was able to monetize his own jumps: In 2015 he signed a sponsorship deal with Reebok to outfit him during his intense training sessions, photos of which he posts to his nearly 2.7 million followers. The man makes $7 million annually from sponsors, some of who are steeped in the fitness world and lean on him for his gym cred. Reebok announced the deal by posting a video of Watt breaking his own box jump record in a pair of newly-released black and yellow Reebok ZPump Fusion shoes.
Which, as it were, brings up a good rule for the average person to follow: If you're going to make money off your insane box jump videos, shoot for the stars and post away. If not, cut the box in half and enjoy a bit more fitness.
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