Training guide
A Copenhagen plank is a side plank with your top leg resting on a bench. The inner thigh of that leg holds your body up while your bottom leg lifts to meet the bench. With your knee on the bench it's the short lever, the place to start; with your ankle on the bench it's the long lever, which loads your inner thigh about half as much again.
It builds inner-thigh strength reliably, and in men's football a short weekly programme built on it cut groin problems. Outside men's football the injury evidence is thin, so treat it there as strength training.
This guide shows you how to set it up and lift, how to build up from squeezes and side-lying lifts, whether to hold or do reps, and how many. It covers what the trials found and who they don't cover, your knees and the soreness people worry about, and when to leave it out, with a 3D demo of the long lever.
Lie on your side on one forearm with the inside of your top knee on a bench, and lift your hips until you're straight from head to knees, your bottom leg rising to meet the bench. With your ankle on the bench (the long lever, shown in our demo), your hip works about half as hard again.
The inner-thigh (adductor) muscles of your top leg hold you up. In 40 male footballers, one of them worked at up to 108% of a maximal effort, among the highest of 8 adductor exercises, and your obliques work harder than in a side plank.
In 652 semi-professional male footballers, a programme built on it lowered the share of players with groin problems in a typical week from 21.3% to 13.5%, and a trial in 202 Japanese schoolboys found less groin pain. The trials counted every groin problem, not only strains.
It builds inner-thigh strength in young athletes, women and youth players. The one trial where most players were women found no clear effect on groin injuries, but it was small, had low compliance and was changed by COVID, so it can't rule an effect out.
The trials started at 1 set of 3 to 5 slow reps a side and built up over several weeks to 12 to 15, 2 or 3 times a week, then dropped to once a week to keep the strength. Built up that way, soreness stayed mild.
Our groin strain guide brings the Copenhagen in last, short lever first. If the inside of your knee aches, put the bench under your knee rather than your ankle.
Its research name is the Copenhagen adduction exercise. Danish researchers singled it out in 2014 as a high-intensity inner-thigh exercise, and it was designed around a slow lowering. The original is done with a partner, who holds your top leg at hip height, supporting the knee and ankle, while you lower your hip towards the floor over about 3 seconds and lift back up. On this site it's done with a bench.
With the inside of your knee on the bench, the lever is short; with the inside of your ankle on it, it's long, which is what our 3D demo shows. Moving the support from the knee to the ankle raised the load on the hip from 0.93 to 1.54 Nm/kg (newton metres per kilogram of body weight) in one lab study, and peak hip torque from 1.1 to 1.7 Nm/kg in another.
Mainly the adductors of your top leg (adductor longus, brevis and magnus, gracilis and pectineus), which hold your body up. Your bottom leg's adductors lift it to the bench, your obliques and the side of your trunk hold the line, and your supporting shoulder takes your weight.
You can hold the top position or lift and lower. The trials that cut groin problems used reps with a slow lowering; holds are the gentler way in, and one programme eased professional players in with 20-second holds before the full exercise.
Several numbers on this page come from EMG (electromyography: electrodes measuring how hard a muscle works over a few reps) or from modelled forces. They show effort, not what a muscle will build.
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In a trial of 35 semi-professional Norwegian men's teams (652 players), teams doing the Adductor Strengthening Programme had groin problems in 13.5% of players in an average week, against 21.3% in teams training as normal: 41% lower risk. The programme was this one exercise at three levels, three times a week through 6 to 8 weeks of pre-season, then once a week through a 28-week season. Later papers describe the levels as side-lying adduction, then the short-lever and long-lever Copenhagen; we could read only the trial's abstract.
A review graded this moderate-quality evidence, but the trial counted every groin problem, from soreness to injury, so its effect on adductor strains alone is uncertain.
In 202 male high-school footballers from 7 schools, 16 weeks of the Copenhagen cut groin pain (relative risk 0.42, where 1 means no difference), and adding Nordic hamstring exercises cut it further (0.19), against usual training. With only 7 schools taking part, the result is less certain than those numbers suggest.
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In Swedish amateur football, an adductor programme copied from the Norwegian one didn't reduce groin injuries. Most of its 125 players were women, teams did it 1.7 times a week in pre-season and 0.7 times in season, and COVID forced changes, so it can't rule out an effect in women. So far, only the trials in male players have shown a benefit.
In 162 rink hockey players followed for a season, monthly Copenhagen sessions weren't linked with fewer groin problems; a past groin injury was. The ice hockey study often quoted, with fewer adductor strains in one professional team, used a general adductor programme and had no comparison group. Earlier groin programmes, pooled across 7 trials and 4,191 players, showed no clear effect.
In young male footballers, eccentric adductor strength (strength while the muscle lengthens under load, as when you lower slowly) rose 35.7% in 8 weeks in 24 players, 8.9% more than the FIFA 11+ warm-up alone in 45 players, and by a large amount in 42 players. Every study that measured strength in a review of 5 found gains, all of them in male football.
Strength rose in 52 female footballers, in 54 youth players including 23 girls, and in 23 teenage taekwondo athletes, though that last study had no comparison group.
In 52 women, 220 reps a side over 8 weeks built as much strength as 394, and one session a week of 16 reps a side kept it for 10 weeks. In 30 rink hockey players aged 14, twice a week built more strength than once a week.
In 57 male youth footballers, 8 weeks of a ball squeeze programme built as much strength as the Copenhagen, with less soreness.
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Across 29 studies, a past groin injury, a higher level of play, less sport-specific training and weaker adductors (on their own and compared with the muscles on the outside of the hip) went with more groin injuries. Groin injuries are about twice as common in men's football as in women's.
A 2025 review found the Copenhagen in 13 of 19 trials of exercise to prevent groin pain. Most measured strength; only one reported fewer injuries.
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From our move page and the trials' descriptions (the slow 3-second lowering and the bottom leg rising to meet the support). The demo shows the long lever; for the short lever, the inside of your knee rests on the bench. One programme used a 30 cm box, raised to hip height in its later levels.
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The movement on the figure: Copenhagen plank
From our move page. Side-lying adduction like this was the first level of the Norwegian programme, as later papers describe it.
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The movement on the figure: Side-lying inner thigh lift (Pilates side kick series)
Move on when you can reach the top of the range in a straight line with no more than mild discomfort; drop back a step if your technique fails or pain goes above 3 out of 10, as the trials did. Ball squeezes, 5 to 10 holds of 5 to 10 seconds (our groin strain guide); side-lying inner thigh lifts, 10 to 12 each side (their move page's dose) or 1 set each side with the reps rising each week from 3 towards 15 (our hamstring and groin workout); the short lever, first as 2 or 3 holds of 10 to 20 seconds each side (our editorial starting point), then 1 set of 3 to 5 slow reps each side, building to 12 to 15 (the trials); then the long lever, starting again at 3 to 5 reps.
1 set each side. The Japanese trial used 3 to 5 slow reps in weeks 1 and 2, 7 to 10 in weeks 3 and 4, then 12 to 15, on 2 or 3 days a week, each rep taking about 3 seconds; the Swedish programme also built from 3 to 5 reps to 12 to 15. The Norwegian programme ran three times a week through pre-season and once a week in season.
Once you've built up, once a week keeps the strength: in one trial, 16 reps a side once a week maintained it for 10 weeks.
2 or 3 holds of 10 to 20 seconds a side, building towards 30: our editorial starting point, close to our advanced core workout's 3 holds of 15 to 20 seconds. Past about 30 seconds, make it harder rather than longer, as our hollow body hold and plank guides advise.
A Danish trial built from 2 sets of 6 to 3 sets of 15 a side, twice a week for 8 weeks, and found a 35.7% gain in eccentric strength. Most Norwegian professional teams used 2 sets of 7 to 10 a side twice a week in pre-season and 2 sets of 8 to 11 once a week in season, rather than the original build-up.
End each set while you can still lower slowly with your body in a straight line. In your first two weeks, stop well short, with 3 or 4 reps to spare, as our plans advise. Going to failure adds little, and people underestimate the reps they have left by about 1.
After your warm-up or at the end of a session. Footballers in the trials did it as part of team training, and our hamstring and groin workout suggests not in the 48 hours before a match.
With the support at the ankle, the hip's inner-thigh load was 1.54 Nm/kg, against 0.93 at the knee, in 24 adults; peak hip torque was 1.7 against 1.1 Nm/kg in 15 adults, one of whom stopped with lower back pain during the long lever. In a muscle-force model of 15 adults, the long lever was top tier for every adductor and the short lever for two of them. These are lab studies of a few reps.
Supports below the knee added a sideways and bending load at the knee in one lab study of 24 adults, which we read as an abstract, and the authors of a training study flagged possible stress on the inside of the knee with a high support. If the inside of your knee aches, put the bench under your knee.
Long-lever and raised versions worked the obliques harder and felt harder: effort rose from 4.6 out of 10 in a side plank to 8.1 in the hardest Copenhagen version, in 15 men. For strong athletes, a weighted hold (loaded to 105 to 150% of body weight) produced up to 48% more force than an unweighted one in 44 rugby players, and over 8 weeks weighted holds built strength in 31 rugby players where unweighted holds didn't.
Keep one straight line from head to feet, and end the set when you can't.
Lower over about 3 seconds. The exercise was designed around the slow lowering, and the trials measured gains in lowering (eccentric) strength.
Starting on the long lever with lots of reps. It's a high-intensity exercise in any form, so start short, with few reps, and build up over weeks.
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Keep your top hip stacked over the bottom one, as in a side plank.
Keep your elbow under your shoulder and push the floor away with your forearm.
Breathe out as you lift, and keep breathing in a hold.
Leave the Copenhagen out while your groin is acutely painful, and follow our groin strain guide, which keeps pain at or below 3 out of 10 at first and brings the Copenhagen in last, short lever first. Its role in rehabilitation is less established than in prevention.
No study has tested the Copenhagen in pregnancy. The NHS advises against starting a new vigorous activity in pregnancy, and with pelvic pain it says to keep active but avoid things that make the pain worse. Our reading: don't start it in pregnancy, and leave it out with pelvic girdle pain; our pregnancy strength workout uses the half-kneeling Pallof press and clamshells instead.
The NHS advises avoiding planks to start with. Our editorial suggestion: wait until side planks on your knees feel comfortable, as in stage 2 of our diastasis recti guide, then start with the side-lying lift.
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With a sore supporting shoulder, train your inner thighs without leaning on it: ball squeezes, side-lying lifts, or band, cable or machine adduction. With an aching inner knee, use the short lever only.
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Women gain strength from it as men do. In one study of 131 athletes, women were weaker in adduction for their body weight (2.34 against 3.08 Nm/kg), so you may stay on the short lever longer (our suggestion).
Side planks, 2 to 3 holds of 15 to 40 seconds each side (our 30-day ab challenge); knee side planks, 3 holds of 15 to 20 seconds each side, and standing band adduction, 3 sets of 10 to 12 each side (our groin strain guide); cable or machine adduction, 2 to 3 sets of 10 to 15 (our editorial starting point); side plank leg lifts for the outer hip, 2 sets of 5 to 8 each side (our 30-day ab challenge); Cossack squats, 6 slow shifts per side (their move page's dose); and the side-lying groin stretch, 20 to 30 seconds, 2 to 4 times each side (its move page's dose), which you skip after a recent groin strain.
3D demoSide plankIntermediate · No equipment
3D demoKnee side plankBeginner · No equipment
3D demoCable hip adductionBeginner · A cable machine
3D demoHip adduction machineBeginner · Strength machine
3D demoSide plank with leg liftAdvanced · No equipment
3D demoCossack squatIntermediate · No equipment
3D demoSide-lying groin stretchBeginner · No equipmentOur hamstring and groin injury prevention workout sets out the three-level programme from the football trials; the advanced core workout uses Copenhagen holds; the hockey, field hockey and squash workouts use it short lever first.
The Nordic hamstring and Copenhagen adduction programmes from the football trials: a 10-week build, three adductor levels, then once a week in season.
15 minIntermediate6 movesA wall, An anchor pointHard core training: ab wheel rollouts, hanging leg raises, L-sits, Copenhagen planks, plank walk-ups and dragon flags.
30 minAdvanced6 movesAn ab wheel, Pull-up barA 50-minute off-ice session for ice hockey: lateral bounds and broad jumps, squats, split squats, single-leg hinges, chin-ups, Copenhagen planks and trunk work.
50 minIntermediate13 movesA wall, A bandA 45-minute strength session for field hockey: bounds and landings, goblet squats, split squats, single-leg hinges, Nordics, Copenhagen planks and trunk work.
45 minIntermediate14 movesA wall, A dumbbellA 35-minute routine for squash players: lunges, split squats, one-leg hinges and side lunges, calf raises, Copenhagen planks, trunk work and forearm lowering.
35 minBeginner14 movesA wall, A dumbbellThe strength workout in our runners' plan offers the Copenhagen plank as the harder side plank, 5 to 10 seconds each side.
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. The American Heart Association says these need immediate medical evaluation.
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For chest pain that feels tight, heavy or squeezing, or spreads to your arms, neck, jaw or back; a headache that starts suddenly and is extremely painful, especially while straining; someone who faints while exercising; palpitations that don't go away, or come with chest pain, breathlessness or feeling faint; severe difficulty breathing; or angina pain that doesn't stop after rest and your medicine. Don't drive yourself to A&E.
If you haven't exercised for some time or have a medical condition, speak to your GP first, as the NHS advises. Get advice before hard straining work if your blood pressure is uncontrolled, or you have heart disease or chest pain when you're active, a pacemaker or defibrillator, diabetic eye disease, glaucoma, a hernia, recent eye or tummy surgery, or you're pregnant, as our breathing guide lists.
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See a GP after any faint, and for dizziness that won't go away or keeps coming back.
A pop high on the inner thigh, then a large bruise, a dent or a gap you can feel, or weakness squeezing your legs together: get it assessed within days, as our inner thigh pain guide says. A teenager with sudden pain at the front or top of the hip bone after a sprint, kick or jump, often with a pop, needs an X-ray the same day, as our groin pain guide says.
Get help from NHS 111 (in the US, urgent care) if it's very painful or getting worse, there's a lot of swelling or bruising, you can't put weight on it or walk more than a few steps, or it isn't getting better after treating it yourself. Call 999 or go to A&E if you heard a crack, the leg has changed shape or points at an odd angle, it's numb or tingling, or the skin has changed colour or feels cold.
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Call 999 or go to A&E for severe hip pain after a fall or injury, if you can't walk or put weight on your leg, or for tingling or loss of feeling in your hip or leg after an injury. Ask for an urgent GP appointment or get help from NHS 111 for severe hip pain that starts suddenly without an injury, a hip that is swollen and hot, or hip pain with a high temperature. See a GP if hip pain hasn't improved after 2 weeks of treating it at home.
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Get advice from NHS 111 if your knee is very painful, badly swollen, locks or gives way, or you can't put weight on it; see a GP if knee pain doesn't improve within a few weeks. Ask for an urgent GP appointment or get help from NHS 111 for sudden or very bad shoulder pain, or if you can't move your arm; see a GP if shoulder pain is getting worse or hasn't improved after 2 weeks.
See a GP if you think you have a hernia: a bulge or lump in your groin, upper thigh or tummy that may get bigger when you cough, sneeze or cry and smaller when you lie down. Get help from NHS 111 if you have a hernia and pain in or around it, a bloated tummy, sickness, constipation, a high temperature or sudden confusion. Call 999 or go to A&E for a femoral hernia (a lump at the top of the thigh) with very bad tummy pain, sickness, being unable to fart or poo, a high temperature or sudden confusion. After an inguinal hernia repair, the NHS says no heavy lifting or strenuous activity for at least 4 to 6 weeks.
It's a hard side plank and inner-thigh exercise that anyone with a steady 30-second side plank can learn, and it built strength in women footballers, rink hockey players, rugby players, taekwondo athletes and active adults. What's specific to football is the evidence on groin injuries.
It cut groin problems in men's football. A programme like it showed no clear effect in amateur football where most players were women, though that trial can't rule an effect out; it wasn't linked with fewer groin problems in rink hockey; and older groin programmes, pooled, showed no clear effect.
Built up from a few reps, soreness was mild (a median of 0 to 2 out of 10) and rare: one case in 208 sessions in teenage hockey players. Starting hard, with lots of reps on the long lever, is the likely cause of bad soreness (our reading). A ball squeeze causes less soreness still.
It does work the obliques harder than a side plank, but its main target is your inner thighs: one adductor reached 108% of a maximal effort, and the long lever was top tier for every adductor in a muscle-force model.
Adductor thickness rose about 18% in 8 weeks in 45 active adults and was gone 4 weeks after they stopped, but in 12 young footballers it added nothing beyond normal training.
Exercising a body part doesn't remove the fat over it: across 13 studies and 1,158 people, training one area didn't reduce the fat there. Our guide to losing thigh fat covers what does.
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Mainly the inner-thigh (adductor) muscles of your top leg, which hold your body up, with your obliques and the side of your trunk keeping you in a line and your supporting shoulder taking your weight. In muscle activity studies, the adductors worked harder than in most other adductor exercises, and the obliques harder than in a side plank.
Start with the short lever, with the inside of your knee on the bench. Moving the support to your ankle (the long lever, shown in our demo) loads your hip about half as much again, so move on once the short lever is easy and your knee is comfortable.
Holds are the gentler start; reps with a slow lowering are what the groin trials used. Begin with 2 or 3 holds of 10 to 20 seconds a side, then switch to slow reps.
The trials started at 1 set of 3 to 5 slow reps on each side and added reps every week or two up to 12 to 15. For holds, 2 or 3 of 10 to 20 seconds a side, building towards 30, then make it harder rather than longer.
Two or three times a week while you build up, then once a week keeps the strength: in one trial, a single weekly session of 16 reps a side maintained it for 10 weeks. The football trial used three times a week in pre-season and once a week in season.
In men's football, as far as the evidence goes, yes: a programme built on it cut the share of players with groin problems from 21.3% to 13.5% in a typical week, and a Japanese trial in schoolboys found less groin pain. The trial counted all groin problems, not only strains, and the benefit was seen in teams that kept it up through the season.
It builds inner-thigh strength in women and youth players. The one trial where most players were women found no clear effect on groin injuries, but it was small, had low compliance and was changed by COVID, so it can't rule an effect out, and in rink hockey it wasn't linked with fewer groin problems. Use it for strength, and know the injury benefit has so far been shown in men.
With the bench under your ankle, the inside of your knee takes a sideways load. Move the bench under your knee (the short lever); if knee pain lasts more than a few weeks, see a GP.
Not while it's acutely painful. Our groin strain guide brings the Copenhagen in last, short lever first, after squeezes and band work. A pop with a large bruise, a dent or weakness needs assessing within days.
A sturdy low step, a firm sofa seat or a partner holding your leg works. With none of these, ball squeezes, side-lying inner thigh lifts and band adduction train the same muscles, and a squeeze programme built similar strength in a trial.
It's harder and does a different job: it adds heavy inner-thigh work and works the obliques harder. Master a steady 30-second side plank first, then use the Copenhagen as the harder step, as our side plank guide does.
No study has tested them. The NHS advises against starting a new vigorous activity in pregnancy, and with pelvic girdle pain it says to avoid things that make the pain worse, so leave them out; our pregnancy workouts use the half-kneeling Pallof press and clamshells instead.
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.
