Despite women proving their abilities on the track time and again, men in the medical establishment, media, and athletic associations have fought to keep women (or at least white women) fragile. Yet before there were running shoes for women, they ran barefoot or in nursing shoes. They ran without sports bras, which weren’t invented until 1977, or disguised as men. They faced down doctors who put them on bed rest and newspaper reports that said women collapsed if they ran a mere 800m. Still today, women face relentless attention to their bodies: Is she too strong, too masculine? Is she even really a woman? Mertens transports us from that first boundary-breaking marathon in Greece, 1896, to today’s most intense ultramarathons, in which women are setting all-out records, even against men.