i was just curious, i consider myself in pretty good shape and what not, i can run roughly 18 min 3 mile run, but lately when i run this, right at about the 2.5 mile mark i get this intense side ach. the thing is, if i choose to ignore it, like i usually do and keep running til i finish, my side will be really sore the next day. i was just curious if anyone else has had this problem or if anyone has any idea what might be causing this? i have an idea that it might be because of hydration problems, and if this is the case, how much water should i be drinking every day with this kind of PT?