Copenhagen Plank: A Complete Guide

Quick Intro

Copenhagen Plank is an Isometrics exercise performed by resting the top foot on an elevated surface, such as a bench, while the bottom leg and hip stay unsupported off the floor, and holding a straight line from head to ankle for time using the top leg’s inner thigh (adductors) to keep the hips from dropping. It applies the familiar side plank shape but shifts almost all of the load onto one leg’s groin muscles instead of spreading it across the whole side of the body.

Equipment Needed

No fixed piece of equipment is strictly mandatory, but a bench, box or another surface at roughly knee height is needed to rest the top foot on. Without something elevated to place the foot on, the position this hold depends on cannot be set up at all.

Why Copenhagen Plank Matters

Strength and endurance dominate here, reflecting both the force the top leg’s inner thigh (adductors) needs to lift the hips and the sustained effort needed to hold that lifted line for the full duration. Balance matters as well, tracking the small corrections needed to keep a narrow, elevated, single-leg-supported position steady.

When to Do It

Copenhagen Plank is an advanced hold, best attempted once a standard Side Plank already feels solid for a reasonable amount of time, since this version asks a single leg’s groin muscles to do work that a full side plank spreads across the whole side of the body. It fits well in a lower-body or injury-prevention session, since a strong adductor is closely tied to hip and groin resilience.

Anyone with a history of groin strain should build up slowly here, starting with short holds and building up gradually, since this exercise directly and heavily loads the exact muscle group most groin injuries involve.

Getting Ready

Choosing a bench or box at a comfortable, stable height and testing the top-leg position briefly before committing to a full hold helps confirm the setup is secure. A few slow, gentle side-lying hip lifts beforehand wake up the adductors before asking them to hold the full position.

Step-by-Step Instructions

Entry. Lie on the side with the top leg resting on the bench, then prop up on the bottom forearm and lift the hips off the floor until the body forms a straight line from head to ankle.

Hold. Keep the hips lifted using the top leg’s inner thigh, brace the core to prevent twisting and breathe steadily for the full duration.

Release. Lower the hips back to the floor under control at the end of the hold, without letting them drop suddenly, then switch sides.

How Many, How Often

Copenhagen Plank is dosed by hold duration, not by reps, since it holds one sustained position per side for the entire set.

One or two holds per side, with a short rest between them, is a reasonable dose here, since the adductor working the hold tends to fatigue well before most people run out of patience to keep holding.

Modifications and Variations

Copenhagen Plank carries two variations, both easier steps that reduce the demand this advanced hold places on the hip.

Easier: Side Plank. The more familiar side-lying hold, supported by the bottom foot on the floor instead of an elevated top leg, spreading the load across the whole side of the body and easing the concentration on one leg’s adductors. This is the natural first step for anyone not yet ready for the full Copenhagen position.

Easier (endurance): Isometric Adductor Squeeze. A simpler, more contained hold that isolates the inner thigh directly without the balance and full-body bracing demands of the plank shape around it.

Progression path: Isometric Adductor Squeeze or Side Plank → Copenhagen Plank.

Common Mistakes to Avoid

Letting the hips sag toward the floor as the adductor fatigues. A sagging hip is the clearest sign the working leg’s inner thigh has reached its limit, not that the shoulder or core has failed. Watching hip height throughout the hold keeps every second of the set useful.

Choosing a bench that is too low for the current level of strength. A lower surface increases the range the hips have to bridge and makes the hold considerably harder. Starting with a higher surface and lowering it gradually as strength improves is a safer approach than jumping straight to a standard bench height.

Rotating the hips forward or backward to cheat the position. Twisting out of a clean side-on line takes load off the target adductor and shifts it elsewhere. Keeping the hips, shoulders and ankles stacked in one plane keeps the exercise doing what it is meant to do.

After Your Set

A seated groin stretch, soles of the feet together and knees dropped gently toward the floor, releases the inner thighs after the sustained adductor load. A few slow hip circles on each side afterward help the hip joints settle before moving on to the rest of the session.

Going Deeper

Building toward a full Copenhagen Plank usually means a standard Side Plank is already comfortable for a reasonable stretch of time, since that earlier hold builds the overall side-body bracing this more demanding version still relies on. Treating the side plank as a prerequisite makes the eventual Copenhagen hold far less of a struggle to set up correctly.

The marker of strength here is a hip line that never breaks, not the number of seconds on the clock. A shorter hold with the body staying perfectly straight builds more adductor strength than a longer one spent slowly sinking toward the floor.

Resisting the hips dropping is trunk and hip control, the subject of the core stability training article. The isometric training article covers how holds of this kind are programmed.

How to Know You’re Improving

• Hold 15 seconds per side with the hips staying level and no sag toward the floor.
• Keep the body in one straight line from head to ankle throughout, with no rotation.
• Reach 30 seconds per side using a standard bench height rather than a raised one.
• Notice the working adductor tiring by the end, well before the shoulder or core show any sign of giving out.
• Lower the bench height further once 40 seconds stops feeling like a challenge.

Muscles Worked

• Adductors (the inner thigh muscles, lifting and holding the hips against gravity through the entire hold)
• Obliques (the muscles along the sides of the waist, bracing the trunk and preventing rotation through the hold)
• Gluteus Medius (a hip muscle on the outer side of the pelvis, helping keep the pelvis level and controlled)
• Transverse Abdominis (a deep core muscle that wraps around the torso like a corset, supporting the trunk to keep the straight-line position steady)
• IT Band and Tensor Fasciae Latae (the connective band running down the outside of the thigh and the muscle that tensions it, assisting in stabilizing the hip through the raised position)

FAQ

Do I need to master a regular side plank before trying this? Yes, that is the recommended path. Side Plank builds the overall bracing and hip control this more demanding version depends on, and jumping straight to Copenhagen Plank without it usually ends in a very short, unstable hold.

Is a bench really necessary, or can this be done with no equipment at all? Yes. The position cannot be set up without something elevated, like a bench or box, to rest the top foot on.

Is it normal for one side to feel much harder than the other? A noticeable difference between sides is common, especially early on, since most people have some imbalance in hip and groin strength. Training both sides evenly over time tends to close that gap.

What should I do if my hips drop almost immediately? Raising the bench height to shorten the range the hips need to bridge, or starting with Isometric Adductor Squeeze to build direct adductor strength first, are both reasonable ways to build toward a longer hold (see Modifications and Variations above).

Can I do this without a bench at all? Not in its intended form, since the elevated top-leg position is what creates the adductor demand this exercise is built around. Side Plank is the alternative for a version that only needs floor space.

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Side Plank and Isometric Adductor Squeeze are the two easier steps building toward this hold.