On Monday, I had what I think was an episode of low blood sugar (hypoglycemia) after exercise. This is apparently common in people with diabetes. I don’t have diabetes, but I am insulin resistant and do have elevated blood sugar at times.
Monday I went to training. I did the elliptical to warm up and then went to do strength training with my trainer. On several exercises, we upped the weight so it was a little more intense than usual. I do this as a circuit where I do one set of each exercise, usually with no rest between exercises except walking to each place. I had my heart rate monitor on and I usually will stop and rest 30 seconds or so if my heart rate is above 140 or so.
On Monday, I noticed that I soon felt really tired. Resting for 30 seconds or a minute to get my heart rate down didn’t help. I also started feeling shaky and nauseated. Finally, about halfway through the third set of exercises, I told my trainer that I was done. I went out to the reception area where my husband was waiting for me. Normally, we then go out to the car. But, I felt like I couldn’t possibly walk out to the car. I sat down at the table and my heart rate quickly came down. But, that didn’t help. I still felt shaky and nauseated and was worried that I would faint.
At some point, I realized that my symptoms would fit with what I had heard about as low blood sugar. I’ve never really experienced it to that extent before, but it seemed to fit. I recalled that I hadn’t eaten much that morning. I had a Kind bar about 3 hours before exercising (about 15g of carbs). Then, right before we went to the Y I had a cheese stick (no carbs) and a small piece of dark chocolate (9g of carbs). At that point, once I thought about that, I had my husband go to the vending machine and he got me a Zbar which had 12g of carbs. A little after eating that, I started feeling better.
While I can’t be entirely sure, I think my problem was low blood sugar. While I don’t eat totally low carb, I do eat lower carb than most people. I usually end up averaging about 100g of carbs a day (70 or 80 net carbs). I think I need to pay attention to my carbs before exercising particularly on the more intense days when I am seeing the trainer.
I read some articles about eating before exercise for people with diabetes, which gave me some ideas. So, this morning I tested my blood glucose when I got up. It was at 94. Then I had a Quest bar (chocolate cookie dough for breakfast) for breakfast. Then, right before leaving for the Y I had a sandwich. I used 2 pieces of 100% wholegrain sprouted grain bread (28g of carbs) with 2 ounces of turkey and a piece of Weight Watcher pepper jack cheese. Normally I wouldn’t eat that much carbs early in the day (I often go a week or two without eating any bread, although I do sometimes eat it and do eat some other grains). When we got to the Y, my blood sugar was at 124, which made sense given what I had eaten.
I went in, did the elliptical and then did my training session. I did not feel awful during it. A couple of times my heart rate went over 140 and I rested for 30 seconds or so, but all went well. When it was over, I didn’t feel nauseated or awful. I did test my blood sugar, which was just over an hour after I had had the sandwich. My blood sugar was 90.
That is actually really low for having eaten a sandwich an hour before. So this really reflects how much exercise had lowered my blood sugar. I knew that exercise lowers blood sugar and diabetics are often told to exercise to help control blood sugar. I just hadn’t thought that it might lower blood sugar so much that I might become hypoglycemic. If my blood sugar was 90 today after having about 30g of carbs at lunch, then it was probably much lower on Monday when I had had much lower carbs that morning than today I had 26 Monday including breakfast, versus 52 today including breakfast. From a net carb standpoint (carbs less fiber) it was 17 Monday versus 30 today. So, chances are my blood sugar on Monday was well below 90 when I got finished exercising and may have gone below 70 to hypoglycemia.
And, I do remember there have been some times that I’ve finished at the Y and felt shaky and a little sick but never as bad as this last Monday. I suspect that was on days when I hadn’t eaten much. So, I’ll be watching this much more carefully going forward.