Popsugar Health & Fitness Workouts Are Crunches Bad For Your Back? The Reason You Should Stop Doing Crunches, According to an Expert 10 July 2018 by Tamara Pridgett View On One Page Photo 7 of 10 ADVERTISEMENT () Start Slideshow Share This Link Copy ← Use Arrow Keys → 7 Elbow Plank Start face down on the floor resting on your forearms and knees. Push off the floor, raising up off your knees onto your toes and resting mainly on your elbows. Contract your abdominals to keep yourself up and prevent your booty from sticking up. Keep your back flat — don't let it droop or you'll be defeating the purpose. Picture your body as a long straight board, or plank. Hold as long as you can. Aim for 20 to 30 seconds in the beginning and work your way up to one minute, as you get stronger. Previous Next Start Slideshow Fitness TipsBack PainCore ExercisesInjury PreventionWorkouts