Crunches for Great Abs
We used to do sit-ups, but because sit-ups are not as efficient and can even hurt your back, we now try and do 
crunches, also known as curl-ups. These are an excellent method of strengthening the abdominal muscles.
What you do is lie down on your back, place your hands either crossed over your chest or cupped behind your head as a shelf to support your head. Care should be taken not to exert pressure on the back of the neck or back of the head. Excess pressure could cause neck injury.
Bend your knees up toward your body, and then curl up your shoulders. There is no need to lift your back off the floor. Merely lifting your shoulders and bending towards your stomach will exercise your abdominals. And since you are not lifting your back up off the floor, your hip muscles remain relaxed. All the effort you are exerting is going into strengthening your abs.
There are many variations on crunches that we will be discussing in the future.
