Dean Karnazes is a famous ultramarathon runner, who has established a number of incredible records.
He has completed 100 mile Western States Endurance Run more than 10 times, 135 miles Death Valley run in 50°C temperatures, and "The Relay", a 199-mile run across California. He is also the first runner who accomplished a marathon to the South Pole at −40 °C.
In this book, he recalls back his tremendous feats. He emphasizes that he is just an ordinary man, but with a strong heart.
I can't say anything but amazing. Especially I was touched by the part where he got bored with his work as an elite business man and began running.