Are we up to number 4 already? Sitting in the living room with the heat on, it is hard to believe that all I wanted on Saturday was ice water on my head! This weekend we rode 111 miles starting in Calistoga and looping around the Vineman course, finishing with a 30-mile out-and-back bit on Silverado Trail Road. The weather was hot and rumor has it that temp's were above 100 degrees in the afternoon.
I took my 5U of Levemir at 5:50 and also 5U Humalog for breakfast plus a correction for a high caused by treating an overnight low. We started the ride around 9 AM and after about an hour of riding, I had dropped a little over a pound despite drinking nearly a full bottle of Vitalyte and another of water. My BG's started to fall but then climbed up again before starting their slow, bumpy decline throughout the rest of the ride. From the Dexcom plot, one can estimate a negative slope of about 60 mg/dL/hour between 1 and 5 PM. I was eating and drinking during this time so it seems like my basal insulin was too high; perhaps I could take an initial bolus to offset the early highs and reduce the basal to prevent the steadily dropping BG's later on.
We weighed ourselves again about 50 miles in and at 92 miles. After 50 miles, my weight was down by about 2.4 pounds. We were at our midway break, and took some time to refuel and rehydrate. By the time I resumed riding, I was about 1 pound down. Soon after that point, the temperatures really started climbing, and I felt pretty bad between miles 65 and 80 (when I had a flat and, incidentally, had a few moments to rest in the shade). I was afraid of running out of water between stops but guess I had been drinking enough because my weight was up one pound by mile 92. I really struggled through the last 10, and especially 5 miles. More than anything, I wanted to stop. I was just so hot and uncomfortable! But eventually I pulled myself back into town. I was feeling a little dizzy and spaced out, although my BG's were fine. I think something may have been going with my electrolytes, but that is a topic for another day.
Here's the Dexcom data. I had disconnected my pump and ate without bolusing right away after the ride; hence you see the post-exercise spike. I tried to refuel as well as possible that evening since I had a 20-mile run planned for the next morning at 6 AM.