Here is a case for proper hydration for youth athletes. An article in the Maryland Gazette outlines what needs to be done for a youth athlete to be properly hydrated on game day.
http://www.hometownannapolis.com/vault/cgi-bin/gazette/view/2007G/06/23-14.HTMWhile the article does talk about how the athlete must drink water before strenuous activity, they also talk about staying hydrated with sports drinks during and just after the activity. The article also address es some of the physical indicators of improper hydration.