I disagree on the 'water only' - as I lost a bird a few years ago that I believed could have been saved had some sugar and salt been added to the water in the first instance (he was found by a non fancier - in good time the day of the race collapsed by a stream but became 'waterlogged' and never recovered) so my birds are only allowed a small amount of water, then electrolytes, as the races get longer and fewer birds are sent - I can tend to them individually - swapping cups over. As for the lactic acid build up - getting them out to exercise the next day, I think is crucial even if its just for a short fly and a bath