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 sundry other gear. But the more Bechdel tries to improve herself, the more her self appears to be the thing in her way. The gifted artist and not-getting-any-younger exerciser comes to a soulful conclusion. The secret to superhuman strength lies not in six-pack abs, but in something much less clearly defined: facing her own non-transcendent but all-important interdependence with others.