i have a question about this i would really want to get answered.
I have heard you can do stomach vacuums EVERY DAY, without overtraining the muscles, is this true?

The transverse abdominis (like ALL muscles in your body) needs 48 hours of rest after a SERIOUS workout. This is because your muscle is actually damaged with microscopic tears during a hard workout and as it rebuilds, it makes itself stronger.

BTW - The TA is a key component of the core. The reason your waist shrinks is because the TA is responsible for holding in your guts. As it is strengthened, it tucks in some and holds your inards in better. This in turn presents a leaner tummy.

thanks for the help! everyone says they feel sore after doing vacuums though.. i dont :S maybe i do them wrong..
and maybe the stomach vacuum isent that intense of an exersice? i could do it 5 days a week and then have 2 days off it, or something like that?

I saw this article years ago in Muscle Media written by Shawn Phillips. In it he talked about these. you can still read a little about them at the following web site near the bottom of the page.

http://www.musclemedia.com/training/BootCamp.asp

The original article had an Awsome picture of Arnold perfoming them, and arnold had an unbelievable midsection, unlike most of today's bodybuilders. He didn't have as much muscle mass in the abdomen, but atleast it wasn't protruding like a rhino's.

Hope this article helps alittle

ive read it before. when you do them, i usually count to 25 when i do them so i guess its around 20 secs holding. is that one rep or one set? ive always wondered this about them. like, how much of it should i do?
3 x 20 sec hold? or should i do 20 sec repetitiones maybe 5 reps and 3 sets or something?

in the context of that article, and the one i read before, one vacuum was one set. In the above article, the vacuum was one part of a circuit, so one vacuum was done for about 20 seconds, then on to the next exercise.