Your abs are made up of four main muscles. The center-most muscle is the rectus abdominis. Underneath this muscle, which you cannot see from the outside, is the transversus abdominis. And at the sides of the rectus abdominis are the obliques. The external obliques lie over the internal obliques. By learning the basic function of each of these muscles, you will know how to focus on each part of the abs during your core workouts.
Rectus Abdominis Exercises
Your rectus abdominis mainly flexes your spine, so you can round your back. Crunches and situps are the perfect exercise for this muscle. Crunches are more effective than sit-ups because you only flex your spine and your lower back remains on the ground. To do situps, you must raise your entire back off the ground, and to do this, you must flex your hips. Therefore, you work your hip flexor muscles, such as your iliopsoas and rectus femoris in addition to your rectus abdominis. It is best to do both of these exercises in your overall core routine. But do only one of these per individual workout.
Transversus Abdominis Exercises
When you do crunches and situps, your shorten and lengthen your abdominal muscles. This is not the only way to work your abs. You can do exercises that keep your muscles in a relatively stable position, where the muscles neither shorten or lengthen to a significant degree. This is called isometric training. If you want to strengthen your transversus abdominis, along with your rectus abdominis and obliques all in one swoop, then perform the plank. All you need to do is get in a pushup position, place your forearms on the ground and hold the position for as long as possible.
Your obliques, as a result of their lateral, or side, location in your torso, allow you to bend from side to side. This is known as lateral spinal flexion. To work both the internal and external obliques, grip a dumbbell in your right hand, stand upright, bend to the left and then bend to the right. Repeat this holding the dumbbell in your left hand after you do the required number of repetitions while holding it with your right hand.
To warm up your body before training your abs, go on an elliptical for 10 minutes. If you don't have access to an elliptical, jog on a treadmill or outside. Then, perform three to four of the aforementioned exercises for your abdominals. Do three sets of 15 to 25 reps per exercise. For the planks, do three sets and hold each set for the maximum time possible. Once you complete the exercises, do three sets of stretches for your abs as part of your cool down. To stretch these muscles, lie face-down on the ground with your body in a straight line. Put your hands down on the ground and elevate your torso by pushing off with your hands, straightening your arms and hyperextending your back so your stomach is protruding forward. You will feel a stretch in your abs as you do this. Hold the stretched position for 30 seconds during each set.