Livre d'Or

Sorry to hear it turned out to be an ordeal! It does sound to me like you trained "enough" to expect to have a good time.

Did you pay a lot of attention to water and food the day before and during the run? Also electrolytes, doesn't have to be gatorade, it can be orange juice with a little salt in. Sounds to me like you were inadequately fueled in some way on the day of the run. "Eat before you're hungry, drink before you're thirsty."

I was just chatting with a friend (as we biked up a hill) that figuring out what one's body needs to keep going is a serious part of the challenge with exercise, and takes a while to get right. It does feel terrible when the body runs out of fuel.