Here is actually the correct way to do them and a better way to describe them than I did up there:
Crunches
Muscles Worked:
The primary muscles worked during crunches are the upper abdominals. Secondarily are the lower abdominals and the obliques.
Equipment Needed:
Crunches can be performed on the floor or on a bench.
Execution:
Lay flat on the floor or a bench. Bend your legs and raise your knees so your legs are perpendicular to the floor. With your hands placed in front of your chin or behind your head, exhale and curl your upper body towards your knees contracting your abs. Hold the contraction for a second then slowly lower your upper body back to its original position.
Form:
Don't arch your lower back during crunches. Keep it slightly rounded. If you have your hands behind your head, make sure you do not pull on your neck. Don't try to lift your whole body off the floor. Keep your lower back in contact with the floor or bench and round your shoulders towards your pelvis.
Range of Motion:
Make sure to fully contract and stretch the abdominals during crunches. The abdominal muscles are only responsible for about the first 30° of motion so the range of contraction is not that great. Let your abdominals stretch at the bottom of the movement but don't let the tension leave.
Comments:
The abs are a muscle like any other and are stimulated by overload. You can hold a weight a few inches from your face while performing crunches to increase the overload and stimulate more abdominal development.
http://www.ast-ss.com/training/exerc...asp?bp=Ab&pn=8 Twisting Crunches
Muscles Worked:
The primary muscles worked during twisting crunches are the obliques and upper abdominals. Secondarily are the lower abdominals.
Equipment Needed:
Flat bench
Execution:
Lie on the floor with your hands behind your head and place your legs across a bench. Exhale and curl your upper body towards the bench rotating your elbow towards the opposite knee.
Control yourself back to the starting position and repeat the motion to the other side.
Form:
Keep your lower back slightly rounded as you perform the crunching motion.
Make sure you do not pull on your neck as you are crunching.
Don't try to lift your whole body. Keep your lower back in contact with the floor at all times.
Range of Motion:
Make sure to fully contract and stretch the abdominals during twisting crunches.
Let your abdominals stretch at the bottom of the movement but don't lie flat and let the tension leave.
Comments:
Obliques get a lot of work as stabilizers during heavy weight training and don't need direct overload.
If you want to do some oblique training you can incorporate twisting crunches without any additional weight.
http://www.ast-ss.com/training/exerc...asp?bp=Ab&pn=2
Linear Mode
