Calvin and Hobbes by Bill Watterson for April 24, 1995
Calvin: This new issue of chewing magazine tells how to set up a mandibular fitness regime! Basically, they recommend interval training: chewing one piece of gum with lots of reps, followed by chewing five pieces of gum at once, so you really work the masseter and buccinator muscles. It's a grueling workout, but you build strength and endurance, so you can come through in a clincher. Hobbes: I'm sure the glory makes it all worthwhile. Calvin: Plus, you develop that "chewer's jaw" that drives the girls wild.