The Copenhagen Plank: Groin Strength for Soccer Players
Groin strains are among the most common injuries in soccer, driven by the constant cutting, kicking, and change of direction the sport demands. The Copenhagen plank is the single best-evidenced exercise for building the adductor (inner-thigh) strength that prevents them.
What the Copenhagen plank is
It's a side plank variation where the top leg is supported on a bench, chair, or a partner's shoulder instead of resting on the ground, forcing the inner thigh of the bottom leg to do the work of holding the body up. That's exactly the muscle group — the adductors — most involved in groin strains.
How to perform it (full version)
- Lie on your side. Rest your top leg on a bench or chair at roughly hip height, with your bottom leg underneath.
- Prop yourself up on your bottom forearm, elbow under your shoulder.
- Lift your hips until your body forms a straight line from ankle to shoulder.
- Hold, keeping the hips level — don't let them sag or rotate.
- Lower with control and repeat on the other side.
Regressions for beginners
The full Copenhagen plank is genuinely hard — most players, including many adults, can't hold it for more than a few seconds when they start. Build up through these steps:
- Bent-knee version: bend the bottom knee to 90 degrees instead of holding the leg straight — this shortens the lever and makes the hold much easier.
- Short holds: start with 10–15 seconds per side rather than aiming for a full minute.
- Assisted: keep the bottom knee lightly touching the floor for extra support until strength builds.
Four-week progression
| Week | Version | Sets x hold |
|---|---|---|
| 1 | Bent-knee | 3 x 10–15 sec per side |
| 2 | Bent-knee | 3 x 15–20 sec per side |
| 3 | Full (straight leg) | 3 x 10 sec per side |
| 4+ | Full (straight leg) | 3 x 15–20 sec per side |
Why it prevents groin strains
Research on professional soccer teams has linked reduced adductor strength — measured relative to the opposing hip muscles — to a significantly higher risk of groin injury. The Copenhagen plank directly and efficiently builds that strength, and teams that adopted it as a regular part of training have shown meaningfully lower groin injury rates in published studies.
The Copenhagen plank pairs with the Nordic curl as the two highest-value injury-prevention exercises in soccer. Both are covered in the Strength Training for Soccer Players guide and support the broader picture in ACL Injury Prevention for Female Soccer Players.