By: Mike Collette (Head Coach and Owner of CrossFit Prototype)
This 5-part blog series will cover the five hardest movements/exercises that we see in CrossFit. For the seven years that I have been in the fitness industry, I have seen a lot and tried a lot of different challenges in pursuit of improving my overall fitness. What I have learned during this time as a fitness instructor is that there are an endless number of different exercises that you can do to attain a desired response and effect. With that said, each one of these movements vary in degrees of difficulty due to particular limiting factors. The biggest limiting factor when it comes to many movements is overall motor control and gross coordination. Beyond the mental aspect of skill acquisition, we find that overall mobility and stability limitations are other areas that can make an exercise seem almost unattainable. Furthermore, some exercises are inappropriate for some individuals based on current movement limitations, prior history of injury, and, you could argue, age.
In this mini blog series I will address (in no particular order) five of the most challenging movements that you might see in a CrossFit class or in any fitness gym for that matter. In this post, I will be tackling the “double under.”

The Double Under

By definition (or how I describe it for that matter), the double under involves the athlete performing a single jump while successfully getting the rope underneath themselves twice on that single jump attempt.
For all of you who are reading this post and are familiar with the double under (DU), this movement has its frustrating moments. A movement that looks so simple when performed gracefully by some of the top CrossFit athletes in the world, the reality is it’s quite the opposite. The motor coordination that is involved with this movement really toes the line between gross motor skills (using bigger body parts for movement) and fine motor skills (use of smaller body parts such as hands, feet, wrists). The act of jumping is a gross motor skill, something that is developed as we grow up. The act of turning your wrists and coordinating your hands is more of a fine motor skill, something that is learned as we develop as well. The combination of gross and fine motor skills is what makes up coordination. This is the extent of how in depth I will get into these motor skills but the important thing to consider here is that coordination (1 of the 10 general physical skills) is imperative to the success of this movement.
The Todd mastering DU's
Jumping Rope:
Jumping rope (not just double unders, there is much more to the jump rope then just performing double unders) is a tremendous conditioning tool that has been used for years to improve endurance and coordination. In addition, the act of jump roping is what I would consider “low-level plyometrics”. Plyometrics by definition “is the act of exerting maximal force in short intervals” (Wikipedia). In the case of using the jump rope (especially when starting out with single unders) the goal isn’t to exert maximum force on each jump but to “rebound” consecutively. This develops muscular coordination and the rate in which the muscle fires to improve the ability to exert force. It doesn’t make sense from a progression perspective and a safety perspective to jump (no pun intended) into high-level plyometrics or hard explosive rebounding jumps such as rebounding box jumps or even big bounding double unders. So the tip here and as we continue: be safe. Don’t go too hard with the double unders, the pattern will come.
Learning phases:
For many people, jumping rope was something of the past. You might be one of those people who start CrossFit classes and pick up a jump rope and say “I haven’t jumped rope since I was a kid!” This is a pretty common scenario. That scenario eventually turns into “I wish I kept jumping rope, I would be able to do double unders by now!” Here’s the good news: “you CAN teach an old dog new tricks.” Learning the double under takes time, patience, persistence and most importantly PRACTICE. If you have a goal of being able to do 1 double under or string 100 in a row, you need to practice on executing the movement.
Here are the learning phases of the double under and how you should approach this movement. I also like to call this “the evolution of the double under.” Each one of these phases isn’t necessary for everyone, but for someone who has never jumped rope in their life, this is a progression I love to use:
1.) Wrists, hands, feet, and posture.
Probably the area when learning the double under that often goes overlooked is taking the time to focus on the fine motor skills and coordinating the wrists and hands to spin the rope. A common fault when just spinning the rope for the first time is the position of the hands and use of the shoulders. The movement of the double under and single under for that matter originates at the hands and wrist, not at the elbow and shoulder. The focus here should be on keeping the elbow in and hands slightly out and down. I describe this as “drawing lines” on a white board. So imagine you have a marker in your hand and you are drawing straight or slightly curved lines on a board vs. drawing big circles. Those big circles would come from your shoulder’s creating a windmill type motion. Focus on just learning the pattern at the hands and wrist and build on that.
In addition, the jump portion should originate from the ball of the foot, elevating and keeping the knees straight. A good “hop” is key to stringing the DU’s together down the road compared to hooking the legs (thinking kicking yourself in the butt). This jumping pattern wastes energy and creates a bigger impact when hitting the ground.
Finally, we take a look at posture. We never want to be in a rounded hunched position when jumping rope. It’s inefficient and weak. What we are looking for is a nice solid upright torso with eyes straight ahead. As we get fatigued you might lose posture but the point of practicing good positions will teach your brain to be in those positions while under fatigue!
 
2.) Single Unders
Once you get the motion down at the wrists, hands, and feet we move onto singles unders. The goal here isn’t tempo as much as its able the ability to get under the rope and maintain position. Having a slight pause between jumps is okay as long as we are maintaining good upright torso position and keeping the mechanics at the wrist, hands and feet.
3.) Rebounding single unders
This step typically coincides with step 2. Sometimes this is already a person’s natural pattern which means you can skip step 2. The rebounding single unders refers to rebounding each hop over and over without a pause between hops. Your weight is on the ball of your foot and you are preventing your heals from making contact with the floor to maximize the stretch reflex. Don’t worry about tempo yet, that will be the next step.
4.) Tempo and elevating your jump
This is hard to explain and understand just by reading (you will see what I mean) so take a look at this video I made in 2013 on tempo and how to perform the double under. Elevating your jump, on the other hand, involves you maintaining the same rhythm and tempo on your singles unders while elevating higher every couple hops. This will help teach your brain (and body) to get off the ground to there is enough clearance for that double under. Think “jump,jump,jump, BIG JUMP” and then maintain tempo.
5.) Attempting a double under
This is the part of the article where you might think the best advice is to jump as high as possible any pray, but that’s not the case! Once we have all the prerequisites of our hands, wrist, feet, posture, rebounding and tempo we have earned the right to attempt a double under. Now when it comes to getting your first double under, chances are that it’s not going to be the prettiest thing in the world. Don’t worry about it. We are sticklers when it comes to ensuring proper technique and solidifying good positions but learning is necessary here and more often than not, failure is a big part of learning. Don’t be discouraged if you can’t do it, it will happen!
So how do we approach the double under if we just just perfected our singles? Well as you know, the double under involves the wrists turning over twice to get the rope underneath your body on a single jump vs. the wrists turning over once to get the rope underneath your body on a single jump. When approaching the double under you can’t think of it as two separate single unders. Rather than that, think of it as a single movement. I like to make make the analogy that the movement at the wrists during the double under is like “beating egg’s backwards”. Your wrists and hands should turn over in a COUNTER CLOCKWISE movement. Any slack in the rope will more than likely lead to an unsuccessful attempt. While thinking about “beating eggs backwards” or that quick 1-2 snap! at the wrist, we then turn our focus to the tempo of the rope going underneath you.
For those of you who know the sound a double under makes when the rope is rapidly going underneath you twice on that single jump, that is the tempo we are talking about. That quick 1-2 is the culmination of the wrists and hands maintaining tension throughout the rope and finishing the second turn over. Don’t forget to jump! Your jump height should increase while maintaining position.
Refer back to the above video link to hear that sound of the double under.
6.) Doubles and singles
You just got your first double under! Awesome and congrats!!! It probably took you multiple attempts, it wasn’t the prettiest or the most efficient but you felt how to create tension and turn the rope over. Now that we are in a position that you can do one, our next goal is to be able to doing double unders on a consistent basis. Don’t get me wrong, you aren’t at the point where you are stringing multiple together yet (or maybe you are) but we want to be able to maintain jumping vs. doing a double under and having to stop. The challenge here for people is that they stop because they get excited they can do one or they don’t have the coordinated pattern to reset their jumping tempo.
Again, we want to maintain a good solid base tempo as seen in the video. Reseting back singles is an appropriate progression before stringing them together.
7.) Consecutive doubles
Once you have the ability to perform double unders, it’s now managing the gross motor skill of jumping and the fine motor skill of moving your wrists which move the rope. For some people, this is a natural movement and they can “feel” the rhythm in the rope. For many, this takes practice and learning. I can’t stress enough about building good habits and patterns whenever you’re a the gym or practicing at home. If you need to sacrifice your body to get multiple double unders, STOP! Developing the proper hand, wrist, and elbow position as mentioned previously is critical and sets you up for further success. If this goes, you only limit your capacity. The same goes for your jumping pattern. If you are hooking your heals, landing hard and losing posture (upright torso) you only limit your capacity down the road.
Practice positions and perfect doubles. If you string two perfect double unders, that’s a win. Work the progression on a weekly basis with proper habits and good things will happen!
8.) Be prepared to repeat the steps
While you are in the learning process of acquiring the double under, some days you might have it and some days you won’t. This is part of the learning process. Practicing the progression drills will only help solidify your double unders. Keep practicing every time your at a CrossFit gym and be safe!