Sit-Ups No, Crunches Yes
You know, no one does sit-ups anymore, but do you know why? The object of sit-ups is to strengthen the abdominal wall muscles by using them to bend the spine up and off the floor. However, two other things happen that not only do not contribute to strengthening the abs, but can actually make things worse.
First, when you pull up the spine off the floor, a lot of pressure is exerted on the lower back, or the lumbar region. The weight of your body and the compression of the vertebrae are not such good things for the back.
The second problem is that when you pull up all the way off the floor you also bring the muscles of the hips into play. This reduces the workout you are trying to give your abdominals because the hips are joining in with the effort, helping the abs and taking away from the efficiency of the exercise that you are doing.
Nowadays we do crunches.
