Go hard or go home - Fascination Ultratriathlon

Ultratriathlon may sound crazy, but nevertheless - or precisely because of this - more and more athletes are becoming enthusiastic about it. Because competitions over the multiple Ironman distance are more than just a physical challenge. Ultratriathlete Daniel Meier conveys the fascination of this sport in his book "Go hard or go home". What is the motivation behind it? Are ultratriathletes really crazy? And how do you prepare for a race like this?.