Double Under Jump Rope
What Is the Double Under Jump Rope?
Double Under Jump Rope is a cardio exercise that improves cardiovascular endurance and overall fitness. It is considered an advanced-level activity, depending on intensity and personal capabilities. The rope passes under the feet twice on every jump, so it has to be turned at roughly double the speed of an ordinary skip while the feet stay together and the hop only rises a few inches higher than usual. That combination of rope speed and timing is what makes it the hardest of the common rope patterns, and it is why the skill either works or fails outright rather than simply getting tiring.
It is best known as a CrossFit movement, where it shows up in conditioning workouts as the high-turnover piece between strength or gymnastics elements. The clearest example is Annie, a benchmark workout that has been on CrossFit.com since 2005 and pairs 50, 40, 30, 20 and 10 double unders with the same descending sets of sit-ups, for time. Competitive jump rope has its own speed and freestyle events built on the same skill. In general training it works as a conditioning interval, a warm-up for court and ring sports once the skill is reliable, and a low-equipment alternative to plyometric work such as Box Jump when space or equipment is short.
The calves do the jumping and absorb every landing, the quadriceps and glutes supply the more explosive push-off, and the forearms and wrists turn the rope twice as often as they would on a single under while the trunk keeps the body stacked and still. In competitive jump rope athletes, consecutive double unders leaned more on the knee than the speed step did, peak ground reaction forces were similar across double unders, the speed step and running, and peak negative ankle power in the two rope skills was 39 to 114% greater than in running. In practice that means the landings are not heavier than running, but the ankle has to absorb and return force far more sharply, and the knee takes a bigger share of it than it does in an alternating-foot pattern.
It suits people who already have the rope under control. A steady minute of the plain Jump Rope bounce without catching, with quiet arms and the legs straight underneath, is the realistic entry point, and Alternating Foot Jump Rope or High Knee Jump Rope are better places to spend rope time until then. Among the variations, Side-to-Side Jump Rope adds lateral travel and High Jump Rope trades cadence for jump height, while this one keeps the jump low and asks the wrists for the speed instead.
Because it is a skill before it is conditioning, it rewards practicing while fresh rather than only meeting it deep in a workout. Short blocks of clean reps early in a session teach the rhythm faster than long ragged sets, and the timing holds up better later when the legs and lungs are already working.
Muscles Worked
- Gastrocnemius (Lateral Head)
- Primary
- Gastrocnemius (Medial Head)
- Primary
- Soleus
- Primary
- Rectus Femoris
- High
- Vastus Lateralis
- High
- Flexor Carpi Radialis
- Medium
- Gluteus Maximus
- Medium
- Vastus Medialis
- Medium
- Deltoid
- Low
Instructions
- Stand tall with your feet together and under your hips, and the rope resting on the floor behind your heels.
- Hold a handle in each hand with your elbows close to your ribs and your hands just outside your hips.
- Brace your midsection, keep your chest tall and look straight ahead rather than down at the rope.
- Start the rope with your wrists and forearms, keeping your upper arms quiet and your shoulders relaxed.
- Push off the balls of both feet into a hop a few inches higher than a normal skipping bounce, driving through the ankles and knees.
- While you are in the air, turn your wrists twice so the rope passes under your feet two times on that single jump.
- Keep your legs straight underneath you with the toes pointed down, rather than piking at the hips or tucking the knees toward your chest.
- Land on the balls of both feet with soft ankles and knees, in the same spot you took off from.
- Go straight into the next jump and hold an even rhythm instead of racing the rope.
- End the set once the rope starts catching or the jumps turn into a pike, then rest before the next block.
Common Mistakes
Jumping higher instead of turning faster
The second pass of the rope is bought with wrist speed, not hang time, and a big jump only adds landing impact while making the timing harder to hit.
Piking or tucking in the air
Folding at the hips or pulling the knees up changes the arc the rope has to travel through, which is usually why the second pass clips the feet.
Turning the rope with the arms
Swinging from the shoulders and elbows cannot produce two clean turns per jump, and it burns the shoulders out long before the legs are done.
Hands drifting forward and wide
As fatigue sets in the hands creep away from the hips, which shortens the rope's clearance underneath and causes a run of misses.
Heavy, flat landings
Dropping onto the whole foot with a stiff knee sends the impact straight up the shin instead of letting the ankle and calf absorb it.
Grinding through a failing set
Once the rope catches repeatedly the position has already broken down, and every extra attempt is a worse landing than the last.
Injuries
Double Under Jump Rope is a medium risk exercise when performed with proper technique. No single jump is dangerous, but every one of them is a two-footed forefoot landing, and a workout that calls for hundreds of reps piles those landings up quickly. The complaints that follow are the familiar ones: calf and Achilles soreness, pain along the inside of the shin, and a sore forefoot or big toe joint from repeated push-offs. Athletes with limited ankle dorsiflexion or a history of Achilles trouble should treat high-rep double unders as a load to build into, not a skill to test on a bad day.
Keep the hop no higher than the second rope pass needs and the landing quiet, with the weight through the balls of the feet and the knees unlocked so the ankle absorbs the contact instead of the shin. Work on wood, rubber matting or a sprung floor rather than concrete, in shoes with real cushioning under the forefoot. Break the work into small blocks of clean reps with real rest between them rather than grinding one long set, add reps before you add cadence, and count double unders against the same weekly total as the rest of your rope and jumping work. Missed reps whip the rope into the calves and forearms, which stings but does no lasting harm; the cost is that people rush straight back into the next attempt with worse position than before.
The upper body is the other place fatigue shows up. In trained athletes performing consecutive double unders to exhaustion, the shoulder moved into a more internally rotated range as they tired, and they reported stopping because of cardiovascular and shoulder muscular fatigue. That drift is worth respecting: when the wrists stop turning the rope and the arms take over, end the block rather than chase a few more reps, and build shoulder endurance separately so the turning technique holds for longer.
When the impact or the skill is too much, drop back to the Jump Rope bounce or Alternating Foot Jump Rope, or take the rope out of it entirely with Jogging in Place, and use Bodyweight Calf Raise work on other days to build calf and Achilles tolerance. Stop the set for sharp pain in the Achilles, a sudden catch in the calf, shin pain that sharpens as you continue, or pain under the ball of the foot. Soreness that is still there two mornings later, or that returns at the same point of every session, means the rep count needs to come down, and pain that persists should be looked at by a clinician.
Frequently Asked Questions
- Q: What counts as one double under?
One jump during which the rope passes all the way under your feet twice. If it only passes once, that is a single under, which is the plain Jump Rope bounce.
- Q: Do I have to jump higher than on a normal skip?
Only a little. A few extra inches is enough, and the rest of the time comes from turning the rope faster with your wrists. Reaching for height is what turns the jump into a pike and makes the rope catch.
- Q: When am I ready to start learning them?
When you can hold about a minute of steady single unders without catching the rope, with your arms quiet and your legs straight underneath you. If that is still a struggle, spend your rope time on the basic bounce and Alternating Foot Jump Rope first.
- Q: How do I scale a workout that calls for double unders?
Most gyms substitute three single unders for each double under, so 50 double unders becomes 150 singles. A better option while you are learning is to keep attempting them, for example three singles followed by one double, so the skill gets practiced instead of avoided.
- Q: Why does the rope keep hitting my calves and forearms?
Almost always because the hands have drifted forward or out to the sides, or because the second turn was rushed and the rope arrived before you did. It stings but it is not an injury. Stop the set, reset your hands next to your hips, and start again rather than firing off another attempt.
- Q: How many should I do in one set?
Work in small blocks of clean reps, around 10 to 20 at a time when you are learning, with enough rest to start the next block fresh. Long unbroken sets come later, and they arrive faster if the practice reps stay tidy.