1967-Ft Benning Ga..full gear "forced" march..i thought i would drop..something came to me about salt tablets and rehydration from something i had read or heard about so i took the burn packet from my first aid kit and added to my canteen.if i recall it had sodium bicarb and salt..i not only finished standing and in good shape but was able to drop and do push-ups before being allowed to rest.at the time i don't think there was anything going around about electorlyte replacement..