Three independent biological mechanisms cause exercise-associated hyponatremia: evidence from 2,135 weighed competitive athletic performances - Noakes, T D; Sharwood, K; Speedy, D; Hew, T; Reid, S; Dugas, J; Almond, C; Wharam, P; Weschler, L (Proc Natl Acad Sci U S A, 2005)