Ok Gary jogged my memory on the stomach vacuum thread. This is something I use to do in the past if anyone is interested. If You have an office job this is something that could be done throughout the day. If not You can do it for reps.You need to apply Yourself and concentrate for this to work.

1) While sitting place hands on Your knees.

2) Then try to push Your knees down as You push You knees up.

3) Feel it contract Your abs, then exhale.

4) Hold for as long as You can.

Again this can be done for reps or throughout the day. You have to find the amount of time that works for You. Also You can do one leg at a time. Another thing You can do is put Your hands on the outside of Your knees. This will work Your abs a little differant.