Recently, I was aimlessly scrolling through Facebook when I came across a CrossFit post that gave me some pause. The post called on the CrossFit followers to ask questions about movements they were struggling with in the gym, and to leave advice about challenging CrossFit movements that they had mastered. Not surprisingly, the movement that was commonly brought up was…..*drum roll*….double unders.

What IS IT about double unders? Why do we spend months scrolling YouTube for tutorial videos, mastering singles, jumping around like a fool doing “penguin claps” (think: the rhythm without the rope – and much less cute than penguins), and rejoicing when we manage to string two or three together, let alone incorporate them into a WOD?

Double unders are a tricky, fickle movement. They require you to essentially forget everything you know about childhood jump roping (my old trick of jumping to “Miss Mary Mack, Mack, Mack, all dressed in black, black, black” does NOT work – you’re welcome) and adopt a new rhythm and motion pattern. Since the rope passes under your feet twice for every jump, your timing and coordination need to be precise every time, and then CONSISTENTLY to string them together.

But dang, are they a great progressive skill. The calorie torch is REAL (over 1,000 calories per hour – more than running at a 6 mph pace!), they work your legs, arms, shoulder, glutes AND core, and they’re a constant challenge – first you get one, then you string two or three, then 10, then 20 and so forth. And of course, they’re killer for upping your endurance and speed once you’ve mastered the movement.

The secret to getting and improving double unders is a great jump. You have to accomplish enough height and nail the timing for the rope to successfully pass beneath your feet not once, but twice. But jumping requires you to think about the placement of your hands and wrists, PLUS the positioning of your feet and glutes (SURPRISE). It’s a lot!

Lucky for you, we’ve broken down each part of the perfect double under jump in one place and have provided some common pitfalls to watch out for as you master your form.

But First…The Right Equipment

The very first thing you can do to set yourself up for success when it comes to double unders is to make sure you have the right rope. Fortunately, you don’t need to splash out on an expensive, CrossFit Open-worthy rope for it to be successful. Really, the main thing you need to be concerned over is the length of the rope. While it does vary a little from athlete to athlete, you should err on the side of longer length. The rope should barely touch the ground with each rotation. If you don’t hear the distinct “skip skip” with each jump, the rope is too short and you’re MUCH more likely to swat your ankles. On the flip side, a rope that is too long will trip you up. The easiest, foolproof way to size your rope is simple – take a couple of practice swings in front of a mirror or record them on your phone. You should have head clearance of about 4” to 8.”

Additionally, ropes come with varying cord thickness. A thicker cord can be an advantage for newbie athletes because you can get a better feel of where the rope is during your jump. The additional weight also will force you to slow your jumps down, which can help you work on improving your form.

So arm yourself with the right rope and check your stance before you even twirl that rope. Getting started the right way will only serve you well as you master the double under and build your consistency.

Warming Up and The Starting Stance

 Before you even pick up the rope, make sure to take a few minutes to warm up your calves and prepare for the light, agile movement. Do some forward and back hops and some side-to-side hops, starting with both feet and then moving to alternating single legs. Calf raises from the floor or from a barbell plate can also be effective. If you’re seeking a little extra, track and field warm-ups like high knees, hip openers and crossovers (otherwise known as “karaokes”) can also be effective.

Begin with your feet together. Keep it light, bouncing slightly on the balls of your feet. Stand up straight with a proud chest and shoulders down and back. Tuck your elbows at your sides and place your hands at your sides at a 45-degree angle to your body. You should be able to see your hands out of your peripheral vision at all times during your jumps.

Ready to let ‘em rip!

The Do’s and Don’ts for Your Jump

As the title so succinctly puts it, the secret to mastering the double under is the jump. But before you get too cocky (“well, great…I can jump!”), there’s a method to making sure you’re fast enough and high enough so that you can clear the rope twice.

• DO aim for a 4-to-6-inch jump. That’s enough flight time for two spins!

• DO focus your eyes on one static spot throughout your jumps to maintain stability.
• DO keep your core and midline straight as the rope passes under your feet. Think rocket ship!

More on this below.

• DON’T pike and/or donkey kick. Repeat after me: Double under jumps are NOT the same as kips on a pull-up bar! There’s definitely a tendency to do this to prevent tripping, but it’s a negative because it prevents the higher jump you’ll need to get under the rope twice. PLUS – super dangerous for your hamstrings. Correct this by pushing your hips forward.

• DON’T tuck jump. This is a clear indicator that you’re out of control. If you find yourself doing this, concentrate on fully extending your knees and hips, and pointing your toes to the ground. Consider spending some time with some timing drills to smooth out your rhythm.
• DON’T go crazy fast right out of the gate. Yes, dubs are a fast movement. But going at a roadrunner pace will also bring on the fatigue and tear apart your form. SLOW IT DOWN as much as you can, relying on your high jump to keep up the pace you need.

Other Body Part Placements to Consider

 Hands – As previously mentioned, keep your hands tucked in at a 45-degree angle. If they drift out of your peripheral vision, you’ll needlessly shorten your rope. Then you’ll have to jump higher to clear the rope…until you trip up over it and it whips your ankles. #ow

Wrists – Quick, smooth wrist flicks are much more effective for dubs than arm circles. You can mimic this speed and consistency by shaking your hands like you’re drying them. Also, drive your wrists down to the ground as you spin, forcing the rope under you and giving you some extra momentum to jump higher.

Shoulders – Keeping your shoulders and arms wide will change the whole movement pattern – forcing you to use those shoulders and back muscles to propel the rope instead of your wrists. This will wear on your body unnecessarily. It’s just not good form! If you’re having trouble correcting this, here’s a somewhat extreme way to fix it. Set a pair of plyo boxes around 4 feet apart and then jump inside of them. This will force your arms close to your body…or the rope (or…your hands) could smack the boxes. Problem solved.

One More Thing…

Dubs are difficult at best, frustrating at worst. Unless you have impeccable timing (also keeping in mind that most music you might be working out to go with a single under rhythm and not a double under rhythm), it’s just going to take some time and patience to crack them.

But hey, that’s CrossFit, right? So take the time with single unders, rhythm drills, single-double patterns, and eventually – stringing together sets of double unders.

You’ll get there. Promise.