Comics and cultural superstar Alison Bechdel delivers a deeply layered story of her fascination, from childhood to adulthood, with every fitness craze to come down the pike: from Jack LaLanne in the 60s ("Outlandish jumpsuit! Cantaloupe-sized guns!") to the existential oddness of present-day spin class. Readers will see their athletic or semi-active pasts flash before their eyes through an ever-evolving panoply of running shoes, bicycles, skis, and...