If you look at a list of body parts men want to tone, somewhere up near the top, you’ll see abs. Sure, bulging biceps would be great, and you probably wouldn’t mind pecs that pop either. But abs — those elusive, sculpted, six-pack symbol of hyper-fitness — are universally sought on any fitness list. And yet, there is a cottage industry selling misguided, haphazard ab advice. The best abs workouts for men are pretty hard to come by. The main problem is that many workouts don’t take into account that your midsection is actually composed of multiple muscles. The rectus abdominis is probably the one you know best: Running down your centerline from your sternum to pubic bone, this is the muscle people are typically talking about when they describe a six-pack. Then there are the obliques, technically two sets of muscles that run on diagonals beneath the rectus abdominis from your lower ribs to your hip bones. The transverse abdominus is even deeper still, wrapping around the sides of your torso and stabilizing your core. Your lower back muscles also play an integral role in defining your core — both aesthetically (they eliminate some of that side-fat overhang situation) and functional...