Learn about a highly efficient variation of the Copenhagen plank, called the Copenhagen row, that combines the core and hip focus of the plank with an upper-body pulling motion. To perform this exercise, you'll need a light resistance band fixed to a stable surface, like a rack. Get into your preferred Copenhagen plank level - either the knee-bent or straight-leg position - and line yourself up. While holding the plank, pull the resistance band back in a nice, controlled motion, making sure not to sag down or use uncontrolled movements. This dynamic movement introduces an upper-body movement and forces you to work on stability while staying isometric.