Training guide
A double-under passes the jump rope under your feet twice in one jump. It takes a slightly higher, springier bounce than a single, small quick circles of your wrists with your hands by your hips, and the timing to jump just as the rope passes your knees. Start once you can do 50 easy basic bounces in a row.
No trial has tested how to learn them, so the drills here are coaching practice, and we say so. This guide covers the technique step by step on the 3D figure, the drills coaches use, how many to practise while you learn, what double-unders do and don't do compared with singles, looking after your calves and Achilles, leaking, pregnancy and who should wait.
You need more time in the air than for a single. Coach Dave Newman, interviewed for the CrossFit Journal, says the rope doesn't have to turn faster to start with: you need to jump higher. In 76 young men a double-under needed about twice the springiness of a basic bounce. But not much higher: elite skippers cleared the rope by only a few centimetres, with short, ankle-led contacts.
Elbows by your sides and drawn back, hands 10 to 15 cm from the crease at the top of your thighs, and the wrists turning the rope while your arms stay quiet.
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Jump just after the rope passes below your knees. Practise 10 singles then 10 doubles, repeated, rather than one of each.
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The move page's dose: "5 to 10 minutes of short practice sets, ending each before your form slips (our editorial starting point). Once they are consistent, 5 rounds of 20 to 30 with full rest." No study has tested how many are safe while you learn.
Double-unders put 39 to 114% more braking work through the ankle than running in young competitive skippers, and hops can load the Achilles tendon to several times body weight. Keep calf soreness at 5 out of 10 or less and settled by the next morning, as our jump rope guide says.
37% of women CrossFit competitors leaked during double-unders, and 75% of girls who compete in rope skipping leaked, mostly in double- and triple-unders. A pelvic health physiotherapist can help.
The rope passes under your feet twice in one jump; triple-unders pass it three times. The rope has to turn twice while you're in the air, so you need a slightly higher, springier bounce, fast small wrist circles and timing to match. Coach Newman puts the rise at about 4 inches (10 cm), against about half an inch for singles.
"In a double-under, the calves do most of the work," the coach says. The knees help more than in running, and the forearms, wrists and shoulders turn the rope. In long sets, it's the shoulders and lungs that give out.
In 8 elite young male skippers, the rope cleared the feet by about 5 and 9 cm on its two passes at 120 double-unders a minute, falling to about 3 and 4 cm at top speed; ground contacts shortened from 184 to 93 milliseconds, and peak force was about 5.3 to 5.9 times body weight. In 76 young men, double-unders used about 70% of their best rebound jumping.
The Compendium gives double-unders 10.0 METs (multiples of resting energy use), against 8.3 to 12.3 for single skipping depending on pace. The NHS counts skipping as vigorous activity.
Taller people need a longer rope, and a heavier body means more load on each landing, so build up more slowly (our reading). Children who were better at double-unders ran 20 metres faster in a study of 143 schoolchildren. Women and girls leak during them more often.
Small lab groups of trained or elite skippers, many of them teenagers, and surveys of CrossFit athletes. No trial has taught double-unders to beginners.
Our double-unders move page asks for "50 or more unbroken basic bounces with relaxed wrists and quiet landings." Our jump rope guide teaches the basic bounce and sizes the rope.
The basic bounce page asks for "Ankle bounces and pogo hops without calf or Achilles soreness the next day." If your calves are untrained, our springy starter is the bridge.
Use the length that lets you clear it comfortably for singles, as our jump rope guide says, and shorten it a little once your timing is steady. A beaded or medium-weight rope is easier to learn on: the coach thinks a heavier rope helps you feel the rhythm, and says "I don't think beginners should use speed ropes".
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Leave double-unders out while your calf, Achilles or shin is sore, if you leak or feel heaviness when you skip, and in pregnancy if you don't already do them (the warning signs and who-should-wait sections below).
From our double-unders move page and the CrossFit Journal's interview with coach Dave Newman; the stopping rule is our editorial suggestion, after our jump rope guide.
Loading the 3D figure…
The movement on the figure: Double-unders (jump rope)
Move on when the step before is easy, quiet and leaves your calves fine the next morning. Ankle bounces 2 × 15 (our beginner jump rope workout); pogo hops 2 sets of 10 as the higher double-under bounce without a rope (our springy starter); the basic bounce, 5 rounds of 30 to 60 seconds with equal rest (adapted from its move page's dose); then double-unders. There's no demo of triple-unders or crossovers.
Coaching practice from the CrossFit Journal article; the doses are our editorial starting point. No trial has compared ways of learning double-unders.
Bounce low as for singles, then higher as for doubles, so you feel the difference: 3 sets of 10 of each (editorial). The pogo hop shows the higher bounce on the 3D figure.
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10 singles, then 10 doubles, repeated. The coach prefers this to alternating one single with one double, which he thinks teaches you to switch between low and high jumps.
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Jump as high as you like and turn the rope as slowly as you can, to feel the timing.
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A single double-under from a standstill, then from a few singles, before you try to string them (editorial).
In 76 young men, the rebound index (jump height for contact time) was 1.34 in double-unders against 0.60 in basic bounces, about 70% of their best rebound jumping.
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In 8 elite young skippers, contacts were 93 to 186 milliseconds, rope clearance about 3 to 9 cm, and the rope was turned by the wrists with fast ankle work. In 12 elite skippers, faster skipping meant smaller, stiffer bounces. These are small studies of champions.
In 16 young competitive skippers, double-unders and the speed step put 39 to 114% more braking work through the ankle than running, with similar peak forces. Achilles load ran from half body weight in a seated heel raise to 7.3 times body weight in a forward one-leg hop in 8 adults, and hopping on the spot loaded the tendon more than maximal jumps in one person with a tendon sensor. The authors of a hopping study warn that "prolonged hopping may well cause tendon damage".
In 10 trained athletes doing double-unders to exhaustion, they stopped because of tired lungs and shoulders, and their arm action changed as they tired.
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We found no injury surveillance for double-unders and no study of a safe learning dose; reviews of CrossFit injuries give no figures by exercise. In 18 volunteers, a hard circuit with 75 double-unders didn't thicken the tendons over the next 30 minutes, which says nothing about weeks of training.
Across 21 studies, mostly in young people, rope training improved fitness, jumping and sprinting a little, with no clear effect on bone. One review of 15 trials in children mentions shin bone inflammation with too much rope.
2 or 3 short sessions a week with a day between, as our jump rope guide suggests for rope. Expert plyometric guidance allows 48 to 72 hours between jumping sessions.
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5 to 10 minutes of short practice sets, ending each before your form slips (adapted from the move page's dose).
Our editorial ceiling while you learn is about 50 to 100 double-under attempts a session, counting the misses. It comes from an expert table suggesting 80 to 100 foot contacts a session for plyometric beginners, which has never been tested.
5 rounds of 20 to 30 with full rest (adapted from the move page's dose). The coach's mark of mastery is 50 in 30 seconds and 100 in 60 seconds.
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No study has timed it. Our estimate: a first double-under within a few sessions to a few weeks once your singles are easy, and strings of 20 or more within weeks to a few months.
"The rope doesn't have to move quicker to turn a single into a double; the athlete has to jump higher," the coach says.
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The rope shortens or lands too far out. Keep your hands where you can just see them by your hips.
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They tire your shoulders and change the rope's shape. Turn from the wrists.
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You clear the rope by bending, not springing. The move page cues you to avoid piking at the hips or kicking your heels back.
Most people jump as soon as they see the rope. Wait until it passes your knees.
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"We want to spring, not absorb," the coach says. Stay on the balls of your feet.
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Your arms take over and the rope whips your shins. End each set before your form slips.
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Twice a week, after skipping or on other days: slow calf raises 2 × 15 and tibialis raises 2 × 15 (our beginner jump rope workout); single-leg calf raises 2 to 3 sets of 8 to 12 each leg once two-leg raises are easy (our springy starter); isometric calf holds, 3 holds of 30 to 45 seconds (our springy starter; the move page builds to 5); and calf stretches, 30 seconds each side.
3D demoSlow calf raiseBeginner · A wall
3D demoSingle-leg calf raise from a stepIntermediate · A step + A wall
3D demoIsometric calf raise holdBeginner · A wall
3D demoTibialis raiseBeginner · No equipment
3D demoWall calf stretch (gastrocnemius)Beginner · A wall
3D demoSoleus wall stretchBeginner · A wallHops load the Achilles tendon heavily, so calf soreness in the first week or two is common. Keep it at 5 out of 10 or less and settled by the next morning, as our Achilles guide's pain rule says; if it isn't, our suggestion is to repeat the previous week.
Weaker calves may be a risk factor for Achilles tendon pain: limited evidence from 10 cohort studies at high risk of bias. Calf strength work twice a week is a sensible habit while you learn (our suggestion).
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Hops load the Achilles tendon heavily, so build up slowly. A sudden pop at the back of your ankle, with pain and swelling near your heel or not being able to stand on tiptoe on that leg, can mean a torn Achilles: stop, and get help the same day.
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For sore calves or shins, leaking, pregnancy or a first week back: step jacks, 30 to 45 seconds within a circuit, 2 to 3 rounds (adapted from the move page's dose), or a brisk standing march.
The double-under progression is the follow-along session for this guide; the beginner jump rope workout builds the singles first, and the springy starter is the bridge if your calves are untrained.
Learn double-unders in short sets: a springy warm-up, higher bounces without the rope, singles, then double-under practice, with calf work and stretches.
20 minIntermediate9 movesA jump rope, A wallA first jump rope session in about 20 minutes: a springy warm-up, five short rope rounds with equal rest, calf and shin work, and calf stretches.
20 minBeginner7 movesA jump rope, A wallA beginner's springy session: calf strength first, then heel drops, calf springs and gentle bounces, building towards skipping and pogo hops.
20 minBeginner11 movesA wall, A stepA 15-minute barefoot routine for stronger toes, arches, calves and ankles, finishing with balance. You need only a towel, a wall and a resistance band.
15 minBeginner11 movesA wall, Other / check instructionsA 15-minute warm-up and mobility routine for CrossFit-style training: easy rowing, shoulder, wrist, hip and ankle mobility, shoulder-blade work and squats.
15 minBeginner14 movesCardio machine, A wallA 25-minute standing cardio circuit with no jumping: marching, step jacks, sit-to-stands, punches, step-ups and wall push-ups, with a seated option for most moves.
25 minBeginner9 movesA bench or box, A stepOur suggestion: practise double-unders in the Saturday interval slot of the 7-day plan, or alongside the Hyrox plan's sessions.
A full week that mixes intensities: three strength days, two cardio days, a mobility day and an easy day, never seven hard days.
3 training days45 minBeginner5 days a weekA 12-week first Hyrox plan: three runs, two strength sessions and one stations-and-runs session a week, built up to race weights, with a taper and race tips.
5 training days50 minIntermediateIf you leak or feel heaviness, squeeze your pelvic floor just before you start, use shorter rounds or the no-jump options for now, and see our pelvic floor guide or a pelvic health physiotherapist.
Don't start skipping in pregnancy: the NHS advises against starting a new vigorous activity. If you already skip, our suggestion is to drop it when it causes leaking, heaviness or pelvic pain.
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The NHS advises avoiding high-impact exercise to start with. Our postpartum guide covers when and how to build back up to jumping.
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UK guidelines list skipping among the impact activities for active older adults, and note that injuries are more likely in people who aren't used to exercise. Start low and build up gradually.
With sore knees, use the no-jump swaps and our knee guides, including our knee pain when jumping guide. With heart, metabolic or kidney disease, or symptoms when you're active, check with your GP before hard intervals, as our HIIT guide advises.
With spinal fractures, or several fractures from minor falls, the UK consensus advises impact only up to the level of brisk walking, and the Royal Osteoporosis Society suggests talking to your doctor or physiotherapist first. Our osteoporosis guide has more.
Spinal fractures from rope jumping are rare: one case report describes them in an adult without osteoporosis after strenuous skipping. Sudden mid-back pain while skipping is a reason to stop and get it checked (our suggestion).
With proliferative or severe diabetic retinopathy, the American College of Sports Medicine advises avoiding activities that jar the head, such as jumping. With numb feet, our suggestion is low-impact options and a check of your feet afterwards.
Our suggestion, from specialist guidance: if you're taking or have recently taken ciprofloxacin or levofloxacin, or have had a steroid injection near the Achilles, leave double-unders out and ask your GP or pharmacist. These are linked with Achilles tears.
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If you get chest pain or pressure, feel faint or dizzy, are unusually breathless, or your heart races or beats irregularly during exercise, as our plans advise.
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For chest pain that comes on suddenly and doesn't go away, feels tight or like squeezing, spreads to your arms, neck, jaw, stomach or back, or comes with sweating, feeling sick, light-headedness or breathlessness; severe difficulty breathing; someone who faints while exercising; palpitations that don't go away, or come with chest pain, shortness of breath or feeling faint; or a headache that starts suddenly and is extremely painful, especially while lifting or straining, or comes with numbness or weakness, difficulty speaking or loss of vision. The NHS says a bleed on the brain may be more likely when lifting something heavy. Don't drive yourself to A&E.
Call NHS 111 (in the US, your doctor or an urgent care centre) if you're suddenly more short of breath than usual, or have chest pain with feeling sick or a heartbeat that races, skips or flutters.
Stop straight away if you feel any pain or become unwell, the NHS says, and contact 111 if your symptoms worry you or don't go away.
A dull ache in your muscles for a day or two after something new is normal. Joint pain that's sharp, gets worse during a set or lingers into the next day means switching to the easier option, and seeing a GP or physiotherapist if it carries on (our plans' rule). Our muscle soreness guide has more.
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A snap or popping noise at the back of your ankle or heel when it happened, not being able to walk or stand on tiptoe, or swelling and bruising in your calf and ankle. Also a tendon you think you've torn, or severe pain.
Same day: a sudden snap or pop at the back of the heel or calf, or a feeling of being kicked there, then walking flat-footed and being unable to push off, stand on tiptoe or climb stairs. It could be an Achilles tendon rupture or a broken heel bone. Go to A&E or a minor injuries unit, or contact NHS 111.
Heel, ankle or calf pain that hasn't improved after 2 weeks of looking after it yourself, or comes with tingling in your foot. Shin pain that is getting worse or not getting better. Pain in one spot on a bone that hurts to press and gets worse when you jump can be a stress fracture: stop jumping until it's checked.
Pain in one spot on the shin or a foot bone that you can point to with a fingertip, worse with impact and later present at rest or at night: a possible stress fracture. Stop running and jumping until it has been checked.
A knee that is very painful, won't take your weight, is badly swollen or has changed shape, or locks or gives way.
Go to A&E (accident and emergency) if you've injured your knee and it has changed shape, it becomes very swollen very quickly, you felt a pop or snap, you can see bone sticking out, or it's bleeding heavily. Don't drive yourself: ask someone to take you, or call 999 if the pain means you can't move your leg to get there.
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Partly true. You need more time in the air than for a single: about 4 inches of rise against half an inch, by the coach's account, and about twice the springiness in a lab study. But skilled skippers keep the jump small, quick and ankle-led, with only a few centimetres of clearance at speed, and the wrists set the rope speed. Jump a little higher, turn the rope a little faster from the wrists, and time it.
For learners, the coach's advice is the opposite: a slower rope and a slightly higher bounce give you time to see the rope and get the timing.
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The Compendium gives double-unders 10.0 METs, against 11.8 for moderate and 12.3 for fast single skipping. They're harder to do, not a bigger calorie burn.
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The coach prefers 10 singles then 10 doubles, because one-for-one teaches switching between low and high jumps. No study compares them.
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The coach doesn't recommend speed ropes for beginners and thinks a heavier rope helps you feel the rhythm.
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It's common, in 37% of women CrossFit competitors, but it's treatable. See a GP or a pelvic health physiotherapist.
Bounce a little higher than for a single, on the balls of your feet with your body straight, and flick the rope round twice from your wrists, keeping your hands by your hips. Jump just after the rope passes your knees. Practise 10 singles then 10 doubles, repeated.
When you can do 50 or more basic bounces in a row with relaxed wrists and quiet landings, as our double-unders move page asks, and your calves feel fine the morning after skipping.
You need more spring than for a single, quicker wrists and exact timing all at once. Most misses come from hands drifting out, jumping too early, or spinning harder instead of bouncing a little higher.
Only a little higher than for a single: the coach in the CrossFit Journal puts it at about 10 cm, against about a centimetre for singles. Elite skippers clear the rope by just a few centimetres at speed. Tuck jumps and kicking your heels back are faults.
A beaded or medium-weight rope sized so you clear it comfortably, shortened a little once your timing is steady. A heavier rope helps you feel the rhythm; the coach doesn't recommend speed ropes for beginners.
5 to 10 minutes of short sets, ending each before your form slips, 2 or 3 times a week. While you learn, our suggestion is about 50 to 100 attempts a session. Once they're consistent, 5 rounds of 20 to 30 with full rest.
No study has timed it. Our estimate: a first one within a few sessions to a few weeks once your singles are easy, and strings of 20 or more within weeks to a few months.
Not for calories: the Compendium gives double-unders 10.0 METs, and moderate to fast singles 11.8 to 12.3. They're harder on your calves and Achilles and train spring and timing, so they're a skill to learn rather than a better workout.
No study has set an equivalence. Per minute the energy cost is similar, so if you can't do double-unders yet, swap minutes of doubles for minutes of singles.
They're a calf and Achilles exercise, with more braking work at the ankle than running. Keep soreness at 5 out of 10 or less and settled by the next morning; shin pain that builds, or pain in one spot on a bone, needs checking.
Don't start them in pregnancy: the NHS advises against starting a new vigorous activity. If you already do them, our suggestion is to drop them when they cause leaking, heaviness or pelvic pain.
It's common: 37% of women CrossFit competitors leaked during double-unders. Squeeze your pelvic floor just before you start, use shorter sets or the no-jump options for now, and see our pelvic floor guide or a pelvic health physiotherapist.
Exercise education, not a personal prescription, and clinical review of these guides is pending. Check with a GP before starting hard training if you have a heart condition, chest pain, dizziness or breathlessness when active, and stop for sharp or increasing pain. Health disclaimer.
