Circuit training was designed to perform a set amount of exercises in a row (circuit) without any rest in between each set of the exercise. In this abdominal circuit routine designed for females, the main focus upon this routine is to build and tone up the ab muscles and midsection. You will be targeting all of the major abdominal muscles (obliques, lower abs, upper abs and core strength) through 7 strength and defining abdominal exercises. The key to any circuit training routine is to make sure that you do not rest in between sets or in between exercises until you complete all of the exercises in the circuit. This will keep your metabolic rate up ensuring that you burn as many calories as possible without sacrificing strength. *** Notes : When performing the plank as your final ab exercise, you want to hold your position for 15 to 30 seconds followed by a rest period of 60 seconds.