Dean Karnazes has pushed his body and mind to inconceivable limits, from running in the shoe-melting heat of Death Valley to the lung-freezing cold of the South Pole. He’s raced and competed across the globe and once ran 50 marathons, in 50 states, in 50 consecutive days. In this book, Karnazes chronicles his return to the Western States 100-Mile Endurance Run in his mid-fifties after first completing the race decades ago.