I've read about these in a few places, I checked exrx for instructions and I'm finding some missing/conflicting information.

At exrx they don't mention expelling all the air from your lungs. Is it benificial to expel all the air from your lungs even if it reduces the length you can do it for by at least a third?

How many times should you do a single vaccuum as part of your ab routine?

When I suck in I feel like there are two muscles I am working. One sucks below my rib cage and forms an upside down V-Shape. The other is around my belly button and also a few inches below it, feeling like I'm using part of my abdominals also that V-Shaped lower torso muscle between the abs and your crotch. How should these be emphasized?

I did a search on JSF and didn't find the answers to any of these questions.

Forcibly blow out as much air as possible. This should take 10 seconds. Suck your stomach in to max degree. Don't take in air. hold it as long as possible.

It is easier to start lying down till you are used to it.

It isn't supposed to be easy.

Forcibly blow out as much air as possible. This should take 10 seconds. Suck your stomach in to max degree. Don't take in air. hold it as long as possible.

It is easier to start lying down till you are used to it.

It isn't supposed to be easy.

So should I try to do 8 in a row treating each one as a rep, wait 1-3 minutes in between each one and doing X amount total. . .

So should I try to do 8 in a row treating each one as a rep, wait 1-3 minutes in between each one and doing X amount total. . .
No, I suggest you do 5-6 a day, say before meals, at bed time and etc.

No, I suggest you do 5-6 a day, say before meals, at bed time and etc.

thanks that clear it up a lot.