The One Muscle You Never Use For

"I'm going to talk about my core and then I'm going to point out a couple of unusual muscles that people don't normally mention," he says. "My canonical example is what I call the roller skating muscle. If you only go roller skating once a year, twice a year, when you get home brother, you're going to feel a muscle you didn't know existed." 'Think about your Achilles. Think about all those little, little things that eventually fuck you up'