So this is a quick and dirty 'tutorial' on one of the most common mistakes I see people make when drawing well built characters in more dynamic poses/angles.

They forget that the torso is a round cylinder. So I put together a quick example, albeit not the greatest example, just to roughly demonstrate what a fantastically muscled midriff looks like in a 3/4 angle to help people see why you don't draw abs perfectly symmetrical unless you're doing a straight frontal view.

Even then, abs are not perfect things, vary them up a bit (or a lot if you're going for realism)

But above all else, remember that the body is a series of round ovoids and cylinders. Something will always be obscuring some part of the body.