Quote Originally Posted by Mike T View Post
For what it is worth this paragraph from the second article certainly goes along with my opinion:

"A more recent systematic review of the effects of exercise induced dehydration on performance in long cycling time trials suggested that drinking according to thirst sensations (as opposed to drinking more or less frequently) was associated with better sports outcomes.(22) One of the studies in the review found that exercise induced dehydration of up to 2.3% of body weight significantly improved performance.(23) The explanation for how exercise induced dehydration might improve performance is straightforward: you carry less weight, and you don’t have to interrupt your exercise."

The "carry less weight" is particularly relevant if you have to carry your own water/drink.

I suspect that once all the evidence is in we will end up with advice along the lines of "drink to thirst, eat to hunger" - with the very important qualification that if you know - because of the length/height gain or the temperature - that you will need to drink/eat during an event then start early with a little and often approach.
Sounds very sensible - except that in my experience being very interested in what I am doing suppresses my awareness of thirst, hunger and needing a loo. I have arrived at the end of LDWA events quite comfortable, only to feel an almost insatiable thirst moments after.