People within this realm work so much — and, depending on age, have so many obligations towards their families — that they have to formalize and extremetize leisure in order to rationalize seeking it. It has to involve consumption in some way (buy this running Camelbak!), and planning / long-term commitment (you sign up months before), societal buy-in (knowledge that this is a cool thing that you are doing), and secondary optimization (exercise). Then you can give yourself permission to spend 48 hours doing something exclusively for yourself and your suffering-and-survival as enjoyment.