Daily :D It would help me focus my training.

Too many favourites to easily list ;) But one I do keep returning to is 'The Martian', by Andy Weir. There's a great audio book version read by Wil Wheaton. There's something about the main characters persistence against all the things that are thrown at him that really appeals. It takes inspiration from the NASA mentality of 'working the problem.' Taking the challenge at hand and moving systematically through it. Not just him either, in the story the other teams all working together to overcome various hurdles without giving into despair. I find it inspiring when I revisit it. It reminds me to take one problem at a time, one step at a time. 'Work the problem.'

I don't do it at the moment, but I've tried for short periods of times before. There seems to be a whole wealth of benefits, so I think I should revisit it :) How cold do you go with the water? Have you heard of a Dutch guy named Wim Hof? Also known as 'The Iceman.' He is a huge proponent of cold therapy. If you are getting a lot out of it, it may be worth looking him up.