The Plank With a Twist exercise works your abs and obliques.
Lose 10 pounds fast. Plank with a Twist. Begin on the ground in plank position, balancing on your forearms and toes. If you need to make this easier, rest your forearms on a bench or a chair seat. Now, keep your body still and twist your hips to one side, then rotate the other way to complete one rep. Do 10 to 20 reps.