AG Magazine • Fitness & Performance
Most athletes train the muscles they can see in the mirror. The muscles that decide whether you can sprint, cut, kick, and decelerate without pain sit along your inner thigh, and almost nobody trains them on purpose. When did you last program your groin?
That’s the gap the Copenhagen plank fills. This side-lying isometric hold targets your hip adductors, the groin muscles, and it has become a fixture of strength training and conditioning programs, from academy football to amateur rugby. Why does an exercise that looks this simple attract so much research attention?
Here’s what you’ll get: a clear definition, an honest read of what the evidence shows, a step-by-step setup, and a progression you can start this week. You need only a bench or sturdy box. Whether you compete professionally or simply want a body that keeps moving well for decades, hip adductor strength belongs in your strength training and conditioning plan.
What Is the Copenhagen Plank?
The Copenhagen plank is a side-lying isometric exercise in which your top leg rests on a bench while your body holds a straight line, forcing the hip adductor muscles of the top leg to work against gravity. It strengthens the inner thigh and groin, and it is a staple of strength training and conditioning for sport.
The name comes from the Copenhagen adduction exercise, the dynamic version studied in football injury-prevention research. The plank turns it into an isometric hold: you resist gravity instead of moving through a range. That makes it easier to learn, easier to dose, and a smart entry point for any strength training and conditioning block.
Why Do Weak Hip Adductors Matter?
Your adductors stabilize the pelvis every time you plant a foot. When they lag, other tissues absorb the load. A 2026 prospective cohort study followed 37 female football players in Physical Therapy in Sport and found that 14 (37%) developed groin symptoms. Those players showed lower adductor torque than their healthy peers, and adductor torque asymmetry was among the strongest discriminators the authors tested.
The sample was small, so treat it as a signal, not a verdict. Still, it points to something you can act on: hip adductor strength is trainable.
What Strength Training and Conditioning Research Says About Your Groin
Good strength training and conditioning separates what feels useful from what is proven. So let’s sort the evidence by how far it can carry you.
Does the Copenhagen Plank Prevent Groin Injuries?
It may help, and the strongest evidence comes from the plank’s dynamic cousin. A cluster-randomised controlled trial in male football players reported that the Adductor Strengthening Programme prevents groin problems among male football players. [CITATION UNVERIFIED]
A 2026 systematic review in Apunts Sports Medicine pooled ten randomized trials with 1,099 participants and found consistent gains in eccentric hip adduction strength alongside fewer groin-related symptoms, with higher training volumes working better. For groin injury prevention, that’s encouraging.
Here’s the catch: every one of those participants was male, and the authors say generalizing to women remains limited. The research also centers on the dynamic exercise, so treat the isometric plank as evidence-informed rather than evidence-proven.
Does Adding Weight Make the Hold Stronger?
Possibly. In a 2025 study of 44 male rugby players, weighted isometric Copenhagen holds produced greater torque than bodyweight holds and the long-lever squeeze. In a separate eight-week randomized trial of 31 male amateur rugby players, the weighted group improved its adduction-to-abduction strength ratio more than the bodyweight group, though the difference in adduction strength alone didn’t reach statistical significance.
Does More Strength Mean Better Performance?
Not automatically. In a 2025 quasi-experimental study of 38 male football players, four weeks of Copenhagen and Nordic hamstring work raised eccentric adduction strength by 17%, yet jump performance dropped 5–7%. Strength is a foundation, not a finish line. Your wider strength training and conditioning plan still has to convert it into speed and power.
How Do You Do a Copenhagen Plank Correctly?
Follow these five steps for a clean isometric hold in your strength training and conditioning routine:
- Set the bench. Place a sturdy bench or box beside you, roughly knee height.
- Lie on your side. Put your bottom forearm on the floor under your shoulder and rest your top leg on the bench, with the inside of the knee for an easier lever or the inside of the ankle for a harder one.
- Lift the hips. Press the top leg into the bench and raise your hips until your body forms one line from head to hip. Your bottom leg hangs free beneath the bench.
- Brace and breathe. Keep your ribs down, glutes on, and neck long, and breathe steadily.
- Hold, lower, switch. Hold for your target time, lower under control, then repeat on the other side.
How Long Should You Hold a Copenhagen Plank?
There is no universal dose, and the field knows it. A 2024 survey in BMJ Open Sport & Exercise Medicine found that 84% of teams used the Copenhagen adduction exercise, yet 65% had modified it, and only 11% of elite teams kept the original protocol. Teams adjusted sets, repetitions, progressions, and frequency to fit their players.
Here’s AG coaching guidance, not a research prescription: start with two or three holds of 10 to 20 seconds per side, two days a week. End each hold while you could still manage a few more seconds with clean form. Add time before you add load, and stop any set that brings on sharp groin pain.
How Do You Progress the Copenhagen Plank?
Progress in three stages. Build to three clean 20-second holds with the knee on the bench, then move to the ankle, and only then consider added load, as the weighted-hold studies did. Give each stage two to three weeks, and recheck your form on camera every time you advance.
⚡ PRO TIP
Film one side from the front. If your hips drift backward or your trunk sags, move your top knee onto the bench to shorten the lever and cut the hold in half. A clean 10-second hold is a better investment than a sagging 30.
Who Should Use the Copenhagen Plank, and Who Should Check First?
Is the Copenhagen Plank Safe for Beginners and Older Adults?
For most healthy adults, a short-lever, low-volume version is a reasonable starting point, but the research base skews young, male, and athletic. If you have current groin pain, a recent hip or abdominal surgery, or a history of adductor strain, check with a physician or physical therapist before you begin. Muscular effort is normal; sharp or pinching pain is your cue to stop.
Ask yourself a harder question: are you building strength, or collecting exercises? Pick one progression, track your hold times for six weeks, and let your own numbers answer.
Hold the Line. Build the Base.
Strong adductors won’t make headlines, but they quietly support everything you do on your feet. The Copenhagen plank gives you a low-cost, bench-and-bodyweight way to build hip adductor strength and support groin injury prevention, and it earns its place in any strength training and conditioning plan when you treat it as one tool among many. The evidence is encouraging, not final.
Reframe the goal: you aren’t chasing a heroic hold, you’re building a resilient base that lets you train harder everywhere else. This week, schedule two short Copenhagen plank sessions, film your first set, and write down your hold time so you can beat it in two weeks.
