Okay, 4 weeks ago I participated in a 5K race. After the race they were offering free blood glucose testing, and so I asked them to test me. The result was a worrying 231 especially since I had not eaten for about 11 hours, my last meal being 5lbs. of diced watermelon at 10 pm the night before.
In fact watermelon had been my staple food leading up to the race. Also, I maybe had 2 avocados and a couple of handfuls of brazil nuts during that week, but the previous week I might have eating 10 avocados.
They called over a doctor who asked me a few questions, and told me I most likely had diabetes, but said that I should go to a medical clinic sometime that week and have them do some tests.
Instead of getting tested right away I decided to get Dr. Barnard's book on reversing diabetes and switched my diet to more of what Dr. Barnard recommends: Vegan, no overt fats, and eating foods which are low to medium on the glycemic index, especially legumes. I'm still eating fruits like apples, oranges, grapes, but I'm not eating huge fruit meals like I was before. I'm also restricting my watermelon intake, although yesterday I had some.
So after 3 weeks on the diet, I tested myself again after fasting for 12 hours, and got a reading of 82. The following day it was 85, and today (one week later) it was 85 again.
So what happened? Did eating all that watermelon spike my blood sugar so high that it affected my insulin resistance? Or could just having completed some intense cardio raised my blood sugar because my muscles needed energy and that my glycogen stores were releasing glucose into my veins for my muscles to use.
I have a little testimonial. I was on high fat low carb and passed out after running while driving. I was so low on sugar that my heart palpitated and I passed out at the wheel. BODY NEEDS SUGAR. I think you may have had a fluke blood test. See Joe Best utubes. He is diabetic and making this work.
That is frightening. Did you crash your car? Were you hurt?
My test may have been a fluke, but I also tested high after a 5K race 2 years ago as well. So, I plan on taking my fasting blood sugar before and after the next race I do, but that probably won't be until April or May.
Okay, today I ran my first race since the one after which I got tested with a 231 blood sugar reading.
This time I ran the 10K, and before the race I tested myself. Before the race, I didn't eat anything since the night before. My 10 hour fasting blood sugar read 91 mg/dL. After the race I was rather exhausted. I walked 5 minutes or so back to my car and tested myself again. This time it read a staggering 205 mg/dL. I still hadn't eaten anything. I had only drunk water before during and after the race. Undoubtedly my muscles and liver were releasing lots of glycogen for my muscles to use during the race, and it was still temporarily in my bloodstream after I had recently stopped running.
After the race I ate 4 apples and one tiny banana over the next 2 hours. I decided to test myself again and got a very low reading of 63 mg/dL
So there you have it. Strenuous exercise can definitely raise one's blood sugar levels and thus any data tested after a road race is unreliable at best.