Honestly, I do about 4 sets of 10-20 reps, once a week. I believe abs are fine without much direct work and diet determines whether you even see them. I'm admittedly more interested in strength than aesthetics but I'm not okay with looking like crap. I'd just rather squat and deadlift heavy than be super cut.
That may work for strength athletes but I've seen a few guys with pretty pathetic abs on stage conditioned as fck because they neglected to train them enough...
Any good links to videos about how to do stomach vacuums properly?
everyday. stomach vacuum. im going to bust a Frank Zane in a show next year