Slowman, after a near death overhydration 20 lbs weight gain (10 from my own stupidity...10 more in the medical tent stupidity....) at IMLP 2003, I had a fair amount of discussion with Noakes on this topic. While others can sit with their lab coats on with a smug look on their faces from their "highly accurate" white tower academic papers, I'll go with the field studies from Comrades, Ironman South Africa and Ironman New Zealand that Noakes has conducted.