Life's been busy and I never finished my race report. I guess I'll sum it up here--it went great (mostly)! My swim was slow as usual but I didn't feel too tired afterward. The bike and run were both comfortable, and I was happy to keep my BG's in a decent range. My finishing time was 6hours20min.
Now for more recent news. Last weekend, I did my first 100-mile ride in preparation for my Ironman race. I started in Santa Cruz, rode up Route 1 along the Pacific to Moss Beach (a small town just north of Half Moon Bay) and back. The ride up took 4hr40min. The ride back took 2hr30min. Yes, there was a headwind! (My actual ride time was 6:29 but I took some BG testing breaks!) I was lucky to have a good friend who volunteered to sag me the whole way--what a champ! I tried Hammer's drink, Perpetuem, for the first time. My approach was to eat sort of steadily, instead of ingesting huge carb-bombs every now and then. I figured out the total grams of carb in the whole bottle (162 g) and used a carb ratio of about 50g:1U insulin and spread it out over about 4 1/2 hours. I didn't think of this idea until about an hour into the ride, when my BG was climbing. But, it seemed to work pretty well. I also supplemented with gels and bananas as needed. Perpetuem has protein and a little fat in it, and is more like food than sports drinks. I liked the flavor (orange creamsicle) and it is actually pretty filling. I didn't have any GI discomfort from it, either. Yay.
After the ride, I decided to calculate the total amount of insulin used and the total amount of carbs eaten; I then calculated a "biking basal rate" that assumes I will be eating 47 g carbs per hour. This turned out to be 0.7-0.8 U/hr. I'm thinking of just setting my basal rate to that level and not bolusing at all for any food. Actually, that rate probably will need to go down the longer I ride.
If I can do enough testing, and I can estimate my times reasonably well for the race, maybe I can set up a race day basal rate profile based on what I plan to eat throughout the day, and just avoid bolusing all together. (My biggest fears are dropping low during the race and being unable to absorb carbs.)
I also did some calculations to figure out my carb:insulin ratio during the ride and, depending whether I take into account pre-ride insulin and food (and BG corrections), and whether I lump the basal rate into everything, the rate varies from about 55g:1U to 85-90g:1U. More testing is definitely needed.
Currently, I am predicting about 1:30 for the swim, 7:00-7:30 for the bike and 4:40 for the marathon. Well, we'll see about that last one. My best marathon time is 3:39 but that was not with a 2.4 mile swim and 112 mile ride beforehand!