BG Blowup on Paradise

I enjoyed a late afternoon ride with a friend on one of my favorite short routes, known as the "Paradise Loop." Any cyclist who's spent time in San Francisco will probably know of this classic ride, which goes through Sausalito and then up a 1-2 mile hill to eventually reach Paradise Drive, which loops around the rolling hills of the Tiburon Peninsula. The views from Tiburon of the San Francisco skyline, Angel Island and the Bay are amazing, and there are fewer tourists than in Sausalito. It's a perfect spot for a mid-ride snack at the corner bakery.

Anyway, my BG's (BG = blood glucose or sugar) for the day went something like this:

• 11 AM (1 hour after breakfast): 77, ate 1 gel before a 25-minute walk.
• 1:10 PM: 337 (yikes!) -> 1.55 U insulin + 15 g carbs. I was hungry since I hadn't had food since breakfast and was about to ride for 45 miles. I thought the insulin would cover the carbs + bring my BG down since I'm more insulin-sensitive while riding.
• 1:45 PM: 315, okay it's coming down...
• sometime around 2:30 PM: stopped for 20 minutes to help someone change a flat
• 3:45 PM: 360, on the rise again. This was odd, I thought. I took 3.4 U to cover the food I was about to eat at the stop. I thought I was being overly generous and was surprised to see the BG had risen since it was previously falling and I hadn't eaten anything since then.
• 4:00 PM: 45 g carbs estimated; in retrospect I forgot to account for the steamed milk (1 C), about 15 g.
• 4:15 PM: riding again
• 5:00 PM: 508! Yikes. 3.1 U at 5 and 1 U at 5:20 PM. "Did they put regular vanilla syrup in my milk?" was my first thought. Um, I don't think I can blame them!
• 5:32 PM: 448. Okay at least it's coming down...
• 5:50 PM: 559!? Or maybe not...finished riding.

I had changed my infusion set this morning and wondered if there could have been a problem, so took 7 U by injection at about 6:15. At 6:45 I was 464 and just now at 7:21 PM I am 255. Let's see, that's about a 400 mg/dL drop per hour. No wonder I feel a little shaky. I think it's time for some oatmeal! I have no idea how much insulin is actually active in me, but let's figure it out. If I assume that my infusion site has been okay, then I have only 0.36 U IOB (insulin on-board, or the amount of insulin I've bolused in the past 2.5 hours) from my pump. So my total active insulin is 7.36, which would cover an extra big bowl of oatmeal.

I just tested again and my BG is 213 after 5 more minutes, which means my BG is falling at 504 mg/dL per hour. Okay, I will eat now.
**
I just finished the oatmeal, and it is 7:46 PM. My BG is 137, or falling 228 mg/dL per hour. It looks like I should be okay. I am just hoping I won't be bouncing up again.

There are probably some lessons to take away from this:
1) Exercising at a new time of day can be tricky. I almost never ride in the afternoon, and can usually manage my BG's pretty well on rides.
2) Don't eat when my BG is high and rising, especially if I suspect I may be having infusion site issues. This may seem like a no-brainer but when it's 4 PM and the last substantial meal you ate was at 9:30 AM and you've been riding for 2 1/2 hours, it can be tough! When I saw the 360 at the bakery I thought it was strange but assumed my extra big bolus (for being on a ride) would do the job. Sometimes when I am riding I could eat what I ate today with maybe 1 U or less. So 3.6 seemed reasonable to cover the food and to help jump-start the BG's to fall.
3) It would be really cool if I had a gadget that could track this info for me and connect the dots before I end up at 550. I can see it now but didn't have a big picture view out there on the ride.
4) It is necessary to test a lot to figure this stuff out. Test strips should be cheaper for all.
5) I don't follow the advice given to me in 1988 to not exercise with a BG over 250. I'm not saying that it's bad advice but it is too vague to account for every situation.
6) I probably should have pulled out my insulin + syringe right away when I saw my BG had started to rise.
7) The Dexcom would have come in handy, but I have one sensor left and am saving it since I don't want to buy a new box soon.
8) Why am I blogging on a Saturday night? Don't I have anything better to do, like go shop for Christmas presents? Riding around with high BG's makes me a little tired, or maybe it's just from a really busy week. Or maybe it's just because I want to stay home and continue reading What Is the What by Dave Eggers!

Well, it's now 8:15 PM and my BG is 182. Do you think it's going up or down?

(Thanks to Blair Ryan, a triathlete who races for UCSD, for inspiring me to do a little analysis on my BG's!)