There are some controversy over ab crunches. When I was young, I was told to do my crunches if I wanted that sweet six pack. Today, several "gurus" claim they dont work. Well, do they work or not? My answer to that is, "It depends". You cannot tone your stomach and abs without an overall change in your diet and full body exercise. Most people who do crunches regularly are fans of the spot reduction theory. The truth is that spot reduction simply doesn’t work. You can waste your time doing crunches the entire day but it’s not going to get rid of that unsightly belly fat.
And if you're trying to get a six pack, you need to get your body fat down to around 10% or less.
You can't keep the weight you've gained in one area of your body and still expect to get a six pack. It doesn't work like that.
You also cannot eat anything you want and finish off with ab crunches to work off all the fat you consumed for the day. Your body doesn't work that way because you are adding muscle and fat to your middle at the same time which can cause your stomach area to grow even bigger.
You need to change your eating habits (lots of protein and less fat) and then you'll find that the crunches will be more effective.
Also make sure that your ab crunches are done in small quantities of controlled movements with short rests in between.
While the exercises below will help tone your middle. If you're really serious about getting a solid six pack, then I highly recommend Mike Geary's book The Truth About Six Pack Abs. It's thorough, and it provides good pictures of the proper ab exercises, and even offers meal suggestions.
Basic crunches:
Lie on the floor or on a bench. Lift up your legs so they are verically aligned with the floor. Place your hands behind your head or below the chin. Breath out and curl yourself upwards towards your knees. Keep your concentration for a few seconds and slowly lower your body back to start.
Twisted crunches:
Lie on the floor or on a bench with your hands behind your head. Place your legs on a bench. Breath out when you lift your body towards the bench, one arm towards the other.
Cable crunches:
Grab the rope and pull it down to your knees. Hold your hands over your head and crunch your body down to the floor untill you are 90 degree vertical.
