There are those of us whose idea of the ultimate physical challenge is the 26.2-mile Boston Marathon. And then there is Dean Karnazes. Karnazes has run 226.2 miles nonstop; he has completed the 135-mile Badwater Ultramarathon across Death Valley National Park — considered the world's toughest footrace — in 130-degree weather; and he is the only person to complete a marathon to the South Pole in running shoes (and probably the only person to eat an entire pizza and a whole cheesecake while running).

Karnazes is an ultramarathoner: a member of a small, elite, hard-core group of extreme athletes who race 50 miles, 100 miles, and longer. They can run forty-eight hours and more without sleep, barely pausing for food or water or even to use the bathroom. They can scale mountains, in brutally hot or cold weather, pushing their bodies, minds, and spirits well past what seems humanly possible.

Ultramarathon Man is Dean Karnazes's story: the mind-boggling adventures of his nonstop treks through the hell of Death Valley, the incomprehensible frigidity of the South Pole, and the breathtaking beauty of the mountains and canyons of the Sierra Nevada. Karnazes captures the euphoria and out-of-body highs of these adventures.

With an insight and candor rarely seen in sports memoirs, he also reveals how he merges the solitary, manic, self-absorbed life of hard-core ultrarunning with a full-time job, a wife, and two children, and how running has made him who he is today: a man with an überjock's body, a teenager's energy, and a champion's wisdom.

"Many would see running a marathon as the pinnacle of their athletic career; thrill-seeker Karnazes didn't just run a marathon, he ran the first marathon held at the South Pole. The conditions were extreme — 'breathing the superchilled air directly [without a mask] could freeze your trachea' — yet he craved more. Also on his résumé: completing the Western States 100-mile endurance run and the Badwater 135-mile ultramarathon through Death Valley (which he won), as well as a 199-mile relay race...with only himself on his team. This running memoir (written without a coauthor) paints the picture of an insanely dedicated — some may say just plain insane — athlete. In high school, Karnazes ran cross-country track, but when his favorite coach retired, he quit the sport. Fifteen years later, on his 30th birthday (in 1992), on the verge of an early midlife crisis, he threw on his old shoes and ran 30 miles on a whim. The invigorating feeling compelled him to pursue the world of ultramarathons (any run longer than 26.2 miles). 'Never,' Karnazes writes, 'are my senses more engaged than when the pain sets in.' Yet his masochism is a reader's pleasure, and Karnazes's book is intriguing. Casual runners will find inspiration in Karnazes's determination; nonathletes will have the evidence once and for all that runners are indeed a strange breed. Agent, Carole Bidnick. (Mar.) Forecast: A 60 Minutes segment on Karnazes airing in March will generate interest, as will a nine-city author tour, which he will complete by running." Publishers Weekly (Copyright Reed Business Information, Inc.)

"Charming and surprisingly quirky, providing the perfect escapist fantasy for couch potatoes and weekend warriors alike." Kirkus Reviews

Dean Karnazes, who was named one of the Top 10 Ultimate Athletes by Outside magazine, is president of EnergyWell Natural Foods in San Francisco.