Walking to the gym today (20min), I tried to see what would happen if I tried vacuuming my stomach in for as long as I am walking. This proved to be very strenuous and burned even after about 5 minutes. By the time I was 3/4 of the way there, I was unable to make my stomach “pop out” by blowing air into it. Just throwing this out as an idea for people who want to develop good transverse abs.
might be a good idea to include during your post workout treadmill session also. ill have to give that a try.