How to- Double Unders
The double-under is a fundamental exercise performed with a skipping rope where the athlete will jump once, and allow the rope to make two passes as opposed to one. Since its first appearance on CrossFit.com in March 2001, the double-under has quickly become a staple of CrossFit. This quick-paced movement supplements seamlessly with almost every other movement we perform and in turn, is used to increase the work capacity of an athlete. In this article, we’ll discuss rope selection, the set-up, points of performance, and progression work to help take your double-unders to the next level.
First and foremost, let’s look at rope selection. To find out what size rope you should use, take a tape measure and measure from bottom of the chest (just below the nipple), down around one foot ensuring the tape measure is underneath the arch of the foot, then back up to the bottom of the chest. This will give you the “round-trip” length of your rope which, with proper jumping form, will suit you perfectly. Next, select the thickness of the rope based on technique, consistency, and then intensity. Remember, the thinner the rope, the more technically consistent you have to be. So, for a beginner I’d recommend a rope with a weight between 4-3 oz (85–113 g).
Now that you have the proper rope, let’s talk set-up. To begin, grip your handles and allow the rope to rest loosely against, or just behind the heels. Standing tall in your braced position, bend only at the elbows until your forearms are parallel to the ground, palms facing up, and hands in front of the torso. This is will be your starting position for the double-under. Next step is to initiate movement of the rope and begin skipping.
To get the rope moving, rotate your hands at the wrist, keeping the elbows close to the body. As the rope rotates overhead and contacts the floor, jump straight up to allow the rope to pass two times underneath the feet. The jump will come from the ankles, so avoid major knee bend or hip closure. Lastly, remember to keep the body as braced as possible; glutes tight, core engaged, chest up, and head neutral.
The points of performance for this movement are as follows:
- Body is braced throughout the movement
- Hand in front of torso
- Rotation is at the wrist not elbow or shoulder
- Jump occurs at the ankle and only when rope contacts the floor
- Rope passes twice beneath the feet
- Jump is straight up and straight down
Lastly, here are two progressions that will help you on your road to double-unders. For the first progression, you’ll practice linking single unders while maintaining the proper form and wrist rotation. The goal for this progression is to reach 100 single unders unbroken. Once you have the single unders down, you’ll move to second progression; the rhythm count. This progression of skipping is perfect for creating the speed and coordination needed for double-unders. For this progression, begin with a 1-1-2-1-1 (single-single-double-single-single) rhythm. To do this, perform one or two single unders, and on the third jump perform a double-under then return to your singles. This progression can be modified for any count, for example, 1-2-1; 2-2-1-1-; etc. No matter what level of skill you are, always remember our basic format of progression; technique, consistency, intensity.