It’s kind of strange, if you think about it, that the sit-up should be a thing in the first place. In what world would we have to lie down and sit up repeatedly, until our bellies are sore? What are ...

We’ve all done it. Stared down at our stomach, groaned, and dropped to the floor to bang out a set of sit-ups—hoping, maybe praying, that each crunch would somehow melt away belly fat. It’s ...