Do note the sponsored links. See the following from the Medical advice section of The West Highland Way race:Originally Posted by Stef F
3) I further recommend, on the basis of the literature evidence, and my interpretation of it, application of nature’s guide to fluid replacement, thirst. We should not be surprised that nature allows some degree of fluid loss while exerting ourselves, before developing thirst. My impression is that, when drinking by thirst, 2-4% weight loss is normal, non-detrimental and hugely (but not totally) reduces the likelihood of EAH. I note the articles which describe these findings accept this state of affairs, identify its advantages, but hold back from recommending 2-4% weight loss directly, although do so indirectly by implying we do not aspire to weight maintenance.
4) Finally, sources of guidance on fluid replacement are provided by the various authoritative bodies, including the International Marathon Medical Directors Association (IMMDA, 2006) which advocates a fluid intake during marathon running of 400-800mls/hr, and the American College of Sports Medicine, 600-1,200mls/hr. Based on the lesser intensity, through greater distance, of the WHW race, you should expect a fluid intake at or below the lower limits of these recommendations. You will note these recommendations, in keeping with much of the literature I have read, demonstrate a difference in opinion on fluid intake between South Africa and the United States, with the Americans generally advocating greater intakes, often advocating weight maintenance and drinking in excess of thirst, if necessary, to achieve that. In drawing your own conclusions, it may help to know the fluid consumptions of the two most seriously ill athletes with EAH from the 2005 race were 500 and 600mls/hr, with sodiums 127 and 120mMol/l respectively (<130 = EAH). The limited evidence from the WHW race to date does not, in my opinion, support the American recommendations.
EAH is exercise associated hyponatremia - water overload - nasty, can even be fatal, sometimes with very little warning.
Reply With Quote