What is less well acknowledged is that unless you perform sit ups in the correct manner you could be loosing up to 80% of the benefits they bring. Nobody wants to exercise hard and not loose pounds and gain muscle. Everything in exercise is about the quality, not so much the quantity which comes with time.

Abdominal muscles can be strengthened when sit ups are done with the maximum care and technique. What is sought with the perfect sit up is bringing your torso up towards your knees from an initial lying down posture, using the abdominal muscle group only.

A mistake many people make is to end up using other muscle groups additionally. Often these muscles are far more powerful, e.g. flexors of the hips and legs, reducing the benefit you receive from your sit ups. This situation is particularly pronounced with straight leg sit ups.

Sit ups can be performed with the maximum gain by using slow methodical movements. Your legs should rest on a chair or bench leaving your legs bent to 90 degrees. Don't twist your body at the top of the movement since this could lead to major injury due to large rotational stresses on the lower back region. As with any exercises the slightest hint of pain should be met with a cessation of the exercise, at the very least for a few minutes recovery time.

What follows is the ideal guide to correct sit ups:

Lie flat on your back with your legs bent so that your knees are bent 90 degrees.
Your feet should be flat on the floor near your buttocks, or alternatively up on a raised platform like a bench or chair.
Do not hold your feet down since this acts to promote other muscle groups e.g. hip flexor muscles.
Bring your hands together behind your neck so as to support your head's weight. Never use your neck muscles to perform this exercise as damage is likely.
People new to this exercise should be sure to avoid jolting or twisting movements, keeping straight is important.
Comfortably exhale on the upward movement towards the knees, inhale on the way down.
Each curl should be initiated at the shoulders, then the top of the back, followed lastly by the lower back region.
Raise your torso to a maximum of 45 degrees, hold the highest position for a short moment, then move downwards.
Do not let your chin touch your chest, try to maintain a straight spine.
If you happen to use an abdominal exerciser the correct sit up position will be being reinforced.

Sit up progress can be assessed by you periodically performing as many sit ups as possible, with the correct postures and movements, in one minute.

As a rough guide to progress average numbers for men when 18-25 years of age are between 35-38 sit ups per minute. 26-35 year olds do 31-34, 36-45's do 27-29, 46-55's do 22-24, 56-65's do 17-20, 65 year olds and above can do 15-18.

Women average 29-32 sit ups at the age of 18-25, 25-28 aged 26-35, 19-22 aged 36-45, 14-17 aged 46-55, 10-12 aged 56-65 and 11-13 when aged 65 and over.