K0Power wrote:I was always under the impression if you wait until your thirsty to take a drink of water you have left it too late...
I think a few relevant points are that:
Firstly, the 'hydrate or die' message has been most strongly pushed by the sports drink industry.
Secondly, much of the research showing a decline in performance with 'dehydration' does not adequately account for confounding factors, especially heat stress. Put someone on an ego and work them till they are sweating buckets and seriously overheated and, no surprise, they fatigue. Work them just as hard but put the in front of a huge fan that will evaporate the sweat and cool them - as would happen when cycling along a real road at speed - and the fatigue level is likely to be much less, even though they have lost just as much fluid.
Thirdly, if there is one thing that our evolutionary history is likely to have gifted us, as hunters who might take days to track prey, is the ability to tolerate significant levels of dehydration.
Of course really severe hydration is a serious thing, but I would bet that for most sports performances, over-hydration is a more serious problem than dehydration, unless the weather is particularly hot. In fact, I have read a number of articles detailing deaths during sports event due to over-hydration. For example, the following, discussing the ides of the author of the book cited above.http://www.outsideonline.com/blog/outdo ... ports.html
Thirst is very probably the most accurate guide to when and how much you need to drink.
"an original thinker… the intellectual heir of Galileo and Einstein… suspicious of orthodoxy - any orthodoxy… He relishes all forms of ontological argument": jane90.