Plank Twists are an isometric exercise that elaborates on the standard plank. The twisting motion at your core will tone your abs and obliques, as well as challenging the muscles of your upper arms as they work at stabilizing your bodyweight. Start by placing a mat on the ground. Lower your body into a Pushup or classic Plank position by placing both palms on the floor shoulder-width apart. Your legs should be fully extended behind you with your toes bent and touching the ground. Your eyes should be looking down and out at the floor in front of you. Keep your head, spine, hips, and legs together in one continuous straight line. Bracing your core, twist your torso away from the floor by lifting your right arm all the way extended upwards towards the ceiling. Only your left hand and your toes should be touching the ground at this point. Now twist your right arm and torso back to the floor so your right palm is back in its original position and your eyes are facing the ground. Alternate the same movement with your left hand leaving the mat and twisting up towards the ceiling and your right remaining on the ground. Return to starting position. This counts as one Twisting Plank. Try to not let your hips dip downwards as you perform this movement. For a less challenging variation, prop your upper body onto your elbows instead of your hands.