The line that divides the muscles of a six-pack vertically can sometimes become separated. This is called diastasis recti and typically occurs during pregnancy. While a slight separation is normal, too much of one can weaken your abdominal muscles and prevent you from getting a flat stomach. Perform specific exercises to close the gap in your abdominal muscles before you resume normal ab workouts.
It's important to figure out if you have diastasis recti before committing to an exercise program for it. To do this, lie on your back with your knees bent and feet flat on the floor. Put the fingers of your right hand above your bellybutton, and lift your head off the floor. If you have diastasis recti, you will feel a gap in your abdominal wall. If more than two fingers can fit in this gap, you have the condition, so consult with your doctor about the appropriate exercises for you.
To start closing the gap in your abdominal muscles, perform modified crunches. Begin by positioning yourself as if doing a normal crunch. With feet flat on the floor, knees bent and hands pressed into your stomach, lift you head off the floor. Be careful not to strain your neck. Lower back down, and repeat.
Leg extensions work your lower abs and encourage the separated muscles to close without overworking them. To start, lie on the floor with your feet flat and knees bent. Keep your abs tight as you lift one leg off the floor at an angle. Keep your back flat on the floor, and hold your leg up for a few seconds before returning to the starting position. Repeat with your other leg.
The pelvic tilt exercise is another gentle way to tone your abdominal muscles and help them heal. To do this exercise, lie on your back with your legs straight and your arms at your sides. Tighten your abs, and while exhaling tilt your pelvis forward. This should press your back into the floor. Relax and repeat 10 times.