10 Minutes Plank Workout: Simple Moves For Stronger Abs (Premium) app for iPhone and iPad

We don’t know too many people who get excited about doing planks. Generally, you stare down your timer as it runs down. And while we’re being candid, let’s just come out and say it: Planks destroy your abs. For a pretty basic isometric exercise, planks strengthen your entire body—they make your core pop, strengthen your lower back, and build your shoulders.
Better yet, you don’t need any equipment, and you can amp up the intensity by widening your stance and bracing yourself with your hands instead of your forearms and elbows.
See for yourself.