Who’s afraid of the big, bad box jump? If you’ve seen the box jump shin badge of honor (giant gash with blood oozing out like a horror movie), you might understand the fear. It does take relative strength and some focus to build enough explosive power from a deep squat position to spring up and land safely on the box. Yes, it’s one of the more complex movements you’ll find on a regular basis at your standard CrossFit box.
A box jump is a plyometric exercise – meaning athletes have to use maximum force to complete the jumps successfully. They are a great tool for your general fitness, working your hamstrings and glutes, plus firing your core and stabilizing your calf muscles and ankles. That’s a lot of power development, especially in your lower body, and can come in handy for other full body movements and for weight training. They’re great for youth athletes, as well as the average person, because the jumping spikes your heart rate, meaning it’s cardio to the max. Pick up the speed, and you’re working your total body and you’re honing your agility.
Now we’ve determined that box jumps are a dream for any conditioning coach and for athletic training and standard WODs alike, let’s address the big elephant in the room. If the athletes do them right, they get big benefits. Do them wrong, and, well, you’re quite likely getting hurt – whether that’s the aforementioned shin scrape or something worse. Talk about daunting. So, how do you figure out what is a good box jump height?
If you’re into CrossFit, the Rx height for male athletes is 24 inches and 20 inches for female athletes. You’ll also probably find 12 inch boxes in the gym for beginners, and 30 inch boxes for athletes with more advanced jumping ability.
If you’re just getting started…
Here’s a good rule of thumb – if you’re brand new to box jumps, and you’re nervous to start jumping, just don’t. At least not right away. Step ups are a great way to get comfortable with the box itself and the athlete’s ability to produce force through their legs
To do a step up, face the box. Driving your heel into the ground, step one foot up onto the box, extending your one leg to straight to get up on the box. The other leg will trail behind. End with both feet planted on the center of the box. To get down, reverse the movement back to the ground. Repeat, switching legs with each step up.
As you build power and improve, you can move to a higher box. To make the movement more challenging, hold a dumbbell or kettlebell in each hand. Do 10-20 reps 2-3 days a week in your training cycle.
For your first box jumps…
If you’re ready to start real box jumps and aren’t sure what box to do, err on the side of lower rather than higher. If you pick a box that’s too high for your jumping ability, you risk scraping your shin on the box, tripping over or kicking the box on the way up. No one expects you to be JJ Watt right away (if you don’t know what I mean, check out his YouTube video).
Your best bet when starting box jumps might be to not use a box at all. You can start with 15-1b plates (make sure to select solid ones, not ones with a hole in the middle for a barbell). Start in a squatting position, spring up and land with both feet on the center of the plate. Work up your speed and reps over time, until the height is easy. Then, add another plate and keep progressing your box jumps that way. Helpful hint – once you’ve stacked three of four 45-lb plates and can jump comfortably, you’re definitely ready for the 20 inch box.
For some ancillary work to improve your jump and leg power up to a box jump, you can throw in some jump rope sets or some simple hops on the floor (forward-and-back, side-to-side). Do two to four sets of 10.
Performing Box Jumps Safely
Even if you’re only jumping a few inches off the ground, get your form in check now. That means warm up first, and then head to the box, Don’t skip this step! Focus on hip flexion and calf stretches, and make sure to get in a couple of step ups before trying a box jump. Going into an explosive move like a box jump with cold muscles – just not a good idea.
To do a box jump:
- Begin in an athletic position, with your feet hip distance apart, your knees and hips slightly bent.
- Bend your knees into a squat. In one explosive movement, swing your arms back and spring up from the balls of your feet to jump on to the box.
- Your landing position is also in a squat. Land softly, letting your hips and knees absorb the shock of the landing. Plant your feet.
- Depending on the training cycle, you can end by either standing vertical or staying in a squat. Get back down either by stepping or performing a gentle depth jump back on the floor, depending on the box height.
If you’re doing box jumps to plates or to lower boxes, you could be able to complete a high volume of jumps. But because it works so many major muscle groups and requires such explosive power, limit the number of box jumps on higher boxes as they get more challenging. Your form could fall apart quickly, meaning you’re at a higher risk of tripping over the box as you attempt a jump.
Testing Your Vertical Jump
If you want to start real box jumps and feel confident in your form, but you’re not sure which box height to start with, test your vertical jump. This tests the power in your lower body to jump straight up. To do this:
- Stand up next to a wall in an athletic position and reach the arm closest to the wall overhead. Your palm should be facing the wall.
- Bend into a squat and jump straight up.
- The jump height can be measured by notations on the hall or by using a free-standing Vertec
Depending on your score, pick a box that is lower than your highest vertical jump.
Hard box or soft box?
If you’re still getting used to box jumps, you might consider utilizng a soft plyo box, commonly referred to as the “soft box” in most CrossFit boxes.
The soft boxes are filled with heavy-duty foam and then wrapped in a durable vinyl cover. They are the same size and shape as the hard plywood boxes, and the jumping and landing mechanics are the same.
The advantage of the soft box is that it’s generally safer. For one, it hurts MUCH LESS if you scrape your skin against vinyl than plywood (I might speak from experience here). So, less fear of failure, anyone?! They also can make your landing mechanics better for your body – the foam in the soft box absorbs some of the shock from your knees and muscle fibers.
On the flip side, soft box jumps can help an athlete perform their plyometric training and increase muscular strength. Why? When you do a box jump onto foam instead of on an unforgiving plywood, the tendons and ligaments surrounding your knees and ankles are forced to overcome the unstable environment. So, it’s the same landing position and the same landing forces, but it’s harder to maintain control.
Other variations of box jumps
So, your jumping is on point, you’ve built up a high volume and the speed is taken care of. What’s next for box jump progression?
Rebound box jumps
These box jumps require speed and coordination in addition to strength and force. I would recommend practicing these on a lower box (like a 12 inch box or a 20 inch box, for example) until you get some confidence.
Jump on to the box and then immediately jump off. Your legs should remain bent at the knees. Immediately, jump back up. You will never get back up to a standing position, and you won’t rest in between jumps.
Burpee box jumps
First you have the force production of a box jump, then the pure cardio of a burpee? A match made in hell.
To do a burpee box jump, complete a standard box jump. Then, after coming off the box, place your hands on the floor outside your feet. Jump back into a burpee, drop your chest to the floor. Push back up to the standing position and complete another box jump.
Careful with the number of reps on this one – you’re going to tire quickly!
Weighted box jumps
This one is a great exercise if your available box height just isn’t much of a challenge anymore. In this box jump variation, you don’t jump higher, but your landing form really needs to be on point and you need the power. Use a weighted vest to perform a set of box jumps, or hold on to a light dumbbell.
Box Jump Overs
With these box jumps, you stand beside the box instead of facing it directly. Jump laterally up on to the box, and then jump down facing the same direction. Land in the same position.
Box Jump Overs No-Touches
In this exercise, you jump laterally, but your feet should never touch the box. As in, you jump COMPLETELY over the box. Yes, it requires even MORE explosive power and you’ll need to jump higher. This one is for the advanced jumpers out there.
Box jumps may seem scary at first. But with a lot of practice in force, power and focus, you’ll be able to conquer this exercise and be stronger and more athletic than ever.
Kendra Whittle is a writer, novice CrossFitter, marathon runner and triathlete. She lives in St. Louis with her husband, three kids and two dogs.