Double Unders: How to Do Them, Mistakes and Drills

A double under is one jump with two rope passes underneath, and it is the exercise most people give up on for reasons that have nothing to do with fitness. They whip their forearms raw, decide they're not coordinated enough, and go back to singles. Nearly always the real problem is a rope three inches too long and elbows that have drifted away from the ribs.

Get those two things right and the skill arrives faster than you'd expect. Here's how the movement actually works, the drills that shortcut the learning, and the mistakes worth checking before you blame your coordination.

How to do a double under

You need a thin cable speed rope, sized so the handle tops sit between your armpit and your sternum when you stand on the rope's midpoint. Do this before anything else; nothing below works on a rope that's too long.

1. Set your arms. Elbows tucked close to your ribs, hands slightly in front of your hips and about 20cm out from your body. Your upper arms barely move during the whole exercise.
2. Find the rhythm on singles. Skip 20 to 30 relaxed singles first, bouncing on the balls of your feet with your knees soft and your torso upright. If your singles are messy, your doubles will be chaos.
3. Spin from the wrists. The rope speed comes from small, fast circles made by your wrists and forearms, not from swinging your shoulders. Imagine flicking water off your fingertips twice per jump.
4. Jump, don't leap. Around 15 to 20cm of air is enough. Keep your feet together, point your toes down slightly and land softly on the balls of your feet.
5. Time the flick. As you leave the floor, accelerate the wrists so the rope passes twice before you land. The second pass should happen just as you reach the top of the jump, not on the way down.
6. Relax your shoulders. Tension travels up: tight shoulders shorten the rope path and cause the rope to clip your toes.

The drills that shortcut it

Skip the "just keep trying" approach and work through these instead.

• Power singles. Do 20 singles jumping slightly higher than normal with normal rope speed. This teaches your body the height a double under needs without any timing pressure.
• The tap drill. No rope. Jump and tap your thighs twice with your hands while you're in the air. Sounds silly, teaches the exact wrist tempo you're missing.
• One in ten. Skip singles and insert one double under every tenth rep, then continue on singles. This trains the transition, which is where most sets fall apart, and it stops you practising failure over and over.
• Rope rehearsal with a handle in each hand. Hold both handles in one hand and spin the rope beside your body at double under speed while jumping. Your wrists learn the tempo without any chance of a whip.

Fifteen minutes of these, three times a week, does more than an hour of frustrated attempts.

Muscles worked and why it's good conditioning

Skipping is calf and Achilles dominant, with your quads and glutes controlling the landing and your forearms and shoulders holding the rope arc. Your abs work harder than you'd think, because a collapsed torso changes the rope path.

The conditioning effect is well supported. A randomised controlled trial that put interval jump rope exercise into a school PE setting found improvements in body composition, cardiorespiratory fitness and glycolipid metabolism in adolescents with overweight and obesity, and a separate trial of 12 weeks of high intensity interval rope skipping in male footballers reported gains in speed and power measures. Neither result is surprising. Rope work is plyometric, it's repeatable, and it gets your heart rate to the top of the range within about 40 seconds.

For the two and a half hours of moderate activity or 75 minutes of vigorous activity a week that the NHS sets out in its physical activity guidelines, double unders count firmly as vigorous, and five minutes of them will tell you so.

Common mistakes

A rope that's too long. Everything else on this list is downstream of it. Too much slack means the rope decelerates in the air and cannot complete two passes, so you compensate by jumping higher and swinging your arms, and then you whip your calf. Measure it properly.

Flared elbows. When your arms drift out, the rope arc widens and shortens unpredictably, and your timing has to change every rep. Keep them pinned.

Jumping too high. More air feels like the answer and makes things worse: you hang at the top, the rope has to travel slower to match, and you land heavy. Small, quick jumps beat big ones every time.

Piking or tucking. Bringing your knees up or bending at the hips is your body's instinctive attempt to buy time. It shortens the rope's clearance under your feet, which causes exactly the trip you were trying to avoid. Stay long, feet together, toes slightly pointed.

Doing too many too soon. Your Achilles tendons adapt slower than your lungs do. Going from nothing to 200 reps in a week is the fastest route to a sore heel that keeps you off both skipping and running for a month.

Workout progressions

Once you can string ten together, these build capacity without wrecking your calves.

• Ladder. 10, 20, 30, 40, 50 double unders with equal rest. Stop the set when form degrades rather than when you trip.
• EMOM. Every minute on the minute, 15 double unders, for 10 minutes. Rest is whatever remains of the minute, so getting faster buys you recovery.
• Mixed intervals. 40 seconds of double unders, 20 seconds rest, 8 rounds. Brutal, efficient, done in four minutes.
• Singles and doubles. 50 singles into 15 doubles, 5 rounds. Teaches you to hit a clean double under with your heart rate already high, which is the scenario that matters in a workout.

Pair skipping with calf and ankle work so the tissue keeps up with the volume. Our guide to calf raises covers the loading side, and high knees is a useful low impact substitute on days when your Achilles is complaining. When you're ready to buy a proper cable, our best skipping rope UK guide covers what to look for, and there's more conditioning work in the workouts section.

Recommended reads

1. The best skipping rope UK
2. Calf raises: technique and progressions
3. High knees: how and when to use them
4. Box jump technique