I'm in the same court as jschwab with the "it depends" answer. I also run like she does, running a half marathon this weekend in fact. I drink 4 16.9oz bottles of water a day on any given day because that keeps me not thirsty. Sometimes on a 10 mile run I'll drink another 16.9oz, sometimes I'll drink double that, and sometimes less. It just depends on the conditions. I don't tally my water intake though, which is think is what you are asking? If I'm thirsty when I am running I drink, if i'm not I don't.