Astoriamedical has posted 5 Top Workout Myths. I love number 1:
Myth 1 - Doing crunches, or abdominal work will decrease fat in the stomach area (If you do thousands of crunches, then you will have a flat stomach.)
This is what some infomercials preach. They state you can obtain a flat, beautiful, stomach by using their simple ab machine. All you need to do is exercise 2 minutes per day, and voila!
Please note, dear reader, you can’t SPOT REDUCE! By doing a specific exercise for a certain muscle does not make fat suddenly vanish. Fat is lost over time by burning more calories than the body consumes on a regular basis.
Doing situps is good because it develops the core strength you need to work up to larger weights, having strong abs will mean your abs will look good, once the fat covering them comes off.
But just doing lots of situps doesn’t equal fab abs. If you flip through the Guinness Book of World Records, the sit up champion of the world does not look ripped…
