Book excerpt: Welcome to Japan, the most running-obsessed nation on earth, where: a long-distance relay race is the country's biggest annual sporting event; companies sponsor their own running teams, paying the athletes like employees; and marathon monks run a thousand marathons in a thousand days to reach spiritual enlightenment. Adharanand Finn - award-winning author of Running with the Kenyans - moved to Japan to discover more about this unique running culture and what it might teach us about the sport and about Japan. As an amateur runner about to turn forty, he also hoped find out whether the Japanese approach to training might help him keep improving. What he learned - about competition, about team work, about beating your personal bests, about form and about himself - will fascinate anyone who is keen to explore why we run, and how we might do it better.