Editing Water intoxication (section)

===Endurance sports===
[[Marathon]] [[running|runners]] are susceptible to water intoxication if they drink too much while running. This occurs when sodium levels drop below 135&nbsp;mmol/L, which can happen when athletes consume large amounts of fluid. This has been noted to be the result of the encouragement of excessive fluid replacement by various guidelines. This has largely been identified in marathon runners as a dilutional [[hyponatremia]].<ref name = "NEJMed1">{{cite journal  |vauthors=Almond CS, Shin AY, Fortescue EB, etal |title=Hyponatremia among runners in the Boston Marathon |journal=The New England Journal of Medicine |volume=352 |issue=15 |pages=1550–6 |date=April 2005  |pmid=15829535 |doi=10.1056/NEJMoa043901|s2cid=42909509 |doi-access=free }}</ref> A study conducted on runners completing the 2002 [[Boston Marathon]] found that thirteen percent finished the race with hyponatremia. The study concluded that the strongest predictor of hyponatremia was weight gain while racing (over-hydration), and hyponatremia was just as likely to occur in runners who chose sports drinks as those who chose water.<ref name = "NEJMed1"/>