I've had some pretty significant ups and downs in training over the past couple of weeks. Over a week ago, I was scheduled to run my second 20-miler. I hydrated the day before, ate right the night before, and went to bed at a decent time to wake up to my 4:15 a.m. alarm. I got up, met with running buddy Nicole, and ran four miles with her before joint the rest of the Blue Sharks group for their run. But in that fourth mile, something happened. I felt a cool rush go through my body, and I suddenly felt weak. I quickly added a Nuun (electrolyte) tab to my water bottle and drank that, hoping it would solve the problem. I just tried to stay with it for the remainder of that mile, as I knew I'd have a couple minutes to rest before starting with the group. But as soon as I sat down on the curb, I noticed how shaky my legs were, and all I felt like doing was going to sleep. Tim had caught up with us at that point, and he expressed some concern over seeing me hunched over on the curb ...