Copenhagen Planks: What They Are, Potential Benefits, and How to Do Them

Core exercises like side planks offer strength and stability, and they help prevent injuries. But there’s one advanced variation that targets muscles regular side planks miss: the Copenhagen plank.

“A Copenhagen plank is a side plank variation in which one leg is supported on an elevated surface, such as a bench, while the other leg remains free, often held underneath the support,” explains Michael Fredericson, MD, a professor of orthopedic surgery at Stanford University in Stanford, California, and head team physician for the Stanford track and field and swimming teams.

The Copenhagen plank’s positioning challenges both your upper and lower body more intensely than traditional side planks. This builds greater strength in key muscle groups, improving athletic performance and reducing injury risk.

Improves Hip Strength and Health

Strengthens Core Muscles

Improves Shoulder Health

If you have cardiovascular issues, musculoskeletal pain or injuries, or other health conditions or injuries that interfere with your ability to safely exercise, talk to your doctor before attempting the Copenhagen plank to see if it’s appropriate for you, Fredericson says.

Use caution if you have a history of shoulder injuries. “It may be too challenging to hold the elevated side plank position,” explains Matt Kasee, CSCS, a certified strength and conditioning specialist in Cincinnati. And those with a history of knee issues may find that supporting one leg on an elevated surface is too stressful for their knees, Kasee adds.

To perform a Copenhagen plank:

• Lie on one side with your bottom forearm and hand firmly on the ground, the elbow directly beneath the shoulder, and both legs extended.
• Place the side of your top foot onto a sturdy box or bench.
• Press the edge of your top foot into the surface of the box or bench and raise your hips off the ground to form a straight line from head to toe.
• Lift the bottom foot off the ground so it hovers a few inches below the top foot.
• Gaze forward while you hold this position.

“You can perform this in reps by raising and lowering your hips or holding your hips up for a set duration,” says Kasee. Start with 30 seconds or 10 reps per side and gradually increase the duration or number of reps as you get stronger.

Don’t let your hips sag toward the ground during the Copenhagen plank. This compromises your alignment and reduces the exercise’s effectiveness. Kasee says this is often because the hip adductors and core aren’t strong enough for the position. “To fix it, slide more of your top leg onto the support,” he suggests.

Another key mistake is shifting your torso forward, which Kasee says is often caused by insufficient strength in the core and shoulders. To fix it, he advises switching to a traditional side plank so you can build strength and endurance in the shoulder and core. Once you master the correct technique, you can try the Copenhagen plank again.

For those with physical restrictions or who are newer to core training, start with basic core exercises loike side planks. Progress to a modified variation of the Copenhagen plank once you feel ready and able, Kasee says.

To perform a modified Copenhagen plank, bend your top leg and place your top knee on the bench instead of your foot. This simple tweak shortens the distance that your body has to support, making the exercise easier. “Then slowly lengthen the plank as you get stronger until only your ankle and foot are on the box,” Kasee suggests.

• No matter your age or fitness level, a strong core is vital to improve your balance and stability, increase athleticism, and prevent injuries.
• The Copenhagen plank, named after a professional sports team from Denmark, is an advanced version of a plank that targets not only your core, but also your shoulders and hips.
• If you have a history of injuries or are new to core training, start with basic plank variations first to build strength before advancing to the full version of the Copenhagen plank.