This is a good exercise for making the good old plank a little more interesting. It is quite subtle though, campers will need to focus.resi
Start in a regular plank position. Dig your elbows and toes in. Brace core.
By digging your elbows in, pull your shoulders forward over your hands. Resist the movement with your feet. Pull forward with elbows, resist with toes.
Rock back to the starting position and repeat.
If tension isn’t created through the body it will just feel like you are rocking back and forth not doing anything.