Reverse Plank! The best glider exercise to use in a core and full body workout. The biggest challenges with the Reverse Plank are to prevent your hips from sagging and to maintain a straight line between your ankle and shoulders. Your abs play a role in this, but most of the work is performed by your lower back, obliques, glutes and hamstrings. You don’t need any equipment or much space, and if you’re short on time, you can still get an amazing workout just doing planks.