reckonerCopenhagen plank
A side plank with the top leg resting on a bench, so the inside of that thigh has to hold your hips up. It is the hardest adductor exercise in this library and one of the very few that has a randomized trial behind it rather than a theory.
Top shin on a chair, lift the hips high.
- Pattern
- Hip isolation
- Trains
- Adductors, obliques, abs
- Kit
- Bodyweight, floor, sturdy surface
- Loading
- Your own bodyweight
- Reckoner prescribes
- 3 holds of 30 to 60 seconds
- Progression step
- 10 seconds on the hold
- Skill
- Technical, worth coaching
- Recovery cost
- Low
- Not prescribed if you have declared
- Hip, shoulder
Muscles worked
How to do it
Set the bench and the shin
Lie on your side with a bench or a chair beside you at about knee height. Put the inside of your top shin and ankle on it, elbow under your shoulder, forearm flat on the floor.
Lift the hips into one line
Press down through the elbow and the top leg and raise the hips until your body makes a straight line. The bottom leg comes off the floor and hangs, or rests lightly against the bench.
Squeeze the inside of the top thigh
The muscle doing the work is the one pulling the top leg down into the bench. Squeeze it deliberately rather than just trying not to fall.
Hold until the hips drop, then swap
The set ends when the hips sag or roll, and the time before that is what to log. Both sides, and let the weaker one set the number.
What goes wrong
Starting with the full version
The straight-leg version on the shin is the hardest one and most people cannot hold it for anything useful. Starting there means a few seconds of bad position and a sore groin.
Rolling the top hip forward
Turning slightly toward the floor makes the hold far easier and takes the adductor out of it. Both hip bones should stay pointing straight ahead.
Going back to it too soon after a groin strain
This is a high effort position for a muscle that is slow to forgive. If the area is still sore, the machine hip adduction lets you pick the load precisely, which this exercise does not.
How Reckoner progresses this lift
Six weeks of this lift, run through the real engine. Nothing below was typed in: the prescription, the decision and the sentence beside it all come from the same code that writes your week.
| Week | Prescribed | What it did |
|---|---|---|
| 1 | 3 x 30 s | Longer hold 30 → 40 sYou held every set at RPE 7, so the hold gains ten seconds. A hold with nothing in the hands climbs on time, because time is the only axis it has. |
| 2 | 3 x 40 s | Longer hold 40 → 50 sYou held every set at RPE 7, so the hold gains ten seconds. A hold with nothing in the hands climbs on time, because time is the only axis it has. |
| 3 | 3 x 50 s | Longer hold 50 → 60 sYou held every set at RPE 7, so the hold gains ten seconds. A hold with nothing in the hands climbs on time, because time is the only axis it has. |
| 4 | 3 x 60 s | Holding steady 60 sYou held every set at RPE 7, and 60 seconds is the top of what this hold was prescribed for. There is nothing to put in your hands to make it harder, so this one has run out of room. It stays where it is. If you want to keep pushing here, swap it for a harder movement when the block ends. |
| 5 | 3 x 60 s | Deload 40% of sets offFive weeks of building, then one week lighter. About 40% of the sets come off. The load holds and your reps stay where you earned them, so you keep the strength and lose the fatigue. |
| 6 | 2 x 60 s | Holding steady 60 sYou held every set at RPE 7, and 60 seconds is the top of what this hold was prescribed for. There is nothing to put in your hands to make it harder, so this one has run out of room. It stays where it is. If you want to keep pushing here, swap it for a harder movement when the block ends. The lighter week is over, so this is back to three sets. |
Real engine output, not an illustration. Every row was produced by running the engine itself when this page was generated.
The full rule, and why the reps move before the load does, is in how Reckoner decides to add weight.
Questions people ask
Does this actually prevent groin injuries?
It is the exercise with the best evidence for it. Thirty-five semiprofessional football teams were randomized, and the group running a program built on this one exercise had the in-season prevalence of groin problems fall from 21.3 to 13.5 per cent, with the risk of reporting one 41 per cent lower1. That is a trial in male footballers, so read it as strong evidence in that population rather than a promise for everyone.
How do I make it easier?
Put the knee of the top leg on the bench instead of the shin, which shortens the lever a great deal. You can also lower the bench, or start by holding the top position for a few seconds at a time rather than one long hold.
Why does it feel so much harder than other adductor work?
Because it is. Across eight hip adduction exercises, peak adductor activity ranged from 14 to 108 per cent of a maximal contraction, and this was one of the two the authors classed as dynamic and high intensity2.
Similar movements
There is no load to ease on this lift, so Reckoner offers one of these the first time it stalls. Each of them has a page.
Sources
- Harøy and colleagues, British Journal of Sports Medicine, 2019. The Adductor Strengthening Programme prevents groin problems among male football players: a cluster-randomised controlled trial thirty-five semiprofessional teams and 652 players cluster-randomized, where a single exercise program built on the Copenhagen adduction cut the average in-season prevalence of groin problems from 21.3 to 13.5 per cent and the risk of reporting one by 41 per cent
- Serner and colleagues, British Journal of Sports Medicine, 2014. EMG evaluation of hip adduction exercises for soccer players: implications for exercise selection in prevention and treatment of groin injuries forty male elite soccer players across eight hip adduction exercises, where peak adductor longus activity ranged from 14 to 108 per cent of a maximal contraction and the Copenhagen adduction and the banded hip adduction were the two the authors classed as dynamic and high intensity