The Copenhagen kick is a more difficult variation of the Copenhagen plank that builds adductor strength and hip stability.
 
In a side plank position, place the top leg on a bench with the bottom leg under the bench. Reduce the difficulty by moving the bench closer to the hips.
 
Lift the hips up until your body is in a straight line with the lower leg off the floor—this is the starting position. At a controlled speed, lift the bottom knee up toward the chest, extend the leg forward, then reverse the motion to return the leg to the starting position.
 
Purpose
The Copenhagen kick strengthens the adductors for strength balance and stability of the hip and to help protect against adductor strains. The kick motion adds another element of stabilization of the hip.
 
Programming
Do 2-3 sets of 10-20 reps.