Video: The science of the six-pack

It seems safe to say that we have all agreed to move beyond the sit-up. That decidedly old-school approach to ab work is not, nor will ever be the path toward what has become the Holy Grail of body betterment: The six-pack. So how do you sculpt the elusive tight, toned middle? Well, by following the scientific principles of body mechanics in their simplest form of course:

“Research shows that you should always train for good mobility in the upper portion of the core and good stability in the lower portion of the core,” says Geralyn Coopersmith, an exercise physiologist and head of the Equinox Fitness Training Institute, “With this foundation, you are able to build a core that functions in peak condition, meaning it’s able to flex, rotate, laterally flex and extend. Research shows that a fit core is most responsive, so muscles will turn on automatically and be engaged no matter what you're doing." Such was the basis for the killer core workout in the video above created by Equinox senior creative program manager for group fitness Lisa Wheeler. “The best moves will have one focus, like rotation for example, but while one muscle group is rotating, others are stabilizing and/or mobilizing to move the body synergistically,” says Wheeler, “That’s going to give you a much deeper abdominal workout than, say, crunches, during which most of the rest of the body is not engaged except the rectus abdominis, which is actually the most superficial muscle in the abdominal bunch.”

Though the exercises designed here may get serious points from the judges on degree of difficulty alone, the outline and principles of movement remain the same no matter what your level. One such abdominal rule to abide by: always start with stability. “It’s sort of like flipping the switch so you’re activating the muscles that might have been sleeping,” says Gregg Cook, the NYC-based Equinox group fitness instructor who lent his perfectly sculpted body to our workout, “When you hold something like a plank, you get a really strong neural signal from the central nervous system to the core. Once everything is lit up, from there you’re just sort of pouring gas on the fire.” See what he means in the video above, shot in the penthouse at the Royalton hotel in New York City, then feel the burn yourself by clicking through the slideshow below for how-to descriptions of each move. Do 3 sets of the indicated reps 3 times per week on non-consecutive days.