You can also bring your right knee to your left elbow, and vice versa, an exercise known as a cross-body mountain climber. Climbing planks require you to start on your forearms, with toes on the ...
To gauge your ability to do a side plank, try this 1-minute challenge. Lie on the floor on your left side, propped up on your left forearm. Keep your elbow and forearm in front of you in an L ...