About a month ago I did an impromptu test of the effect of exercise in cold weather and glucose metabolism.

I had a 100 gram chocolate bar (Green & Black’s Almond Milk Chocolate) before heading out at around 1pm. The temperature outside was around -12° C (around 10° F) and the walk to the park took about 45 minutes. When there I did some ice skating (two half separate hour segments) and walking around, taking pictures. I consumed only water while there.

I left a bit after 6 pm and on the way home stopped at a supermarket and consumed another 100 gram milk chocolate bar (generic store brand) on the way home. Arrive home at 6:55 pm.

After that I made measurements of blood glucose (using a One Touch Ultra Two meter) and of body temperature (using a house brand unit I bought at Shoppers Drug Mart several years ago) taken orally.

According to Wikipedia the commonly accepted normal range for oral temperature is:

36.8° C ± 0.7 (36.1 to 37.5) or

98.2° F ± 1.3 (96.9 to 99.5)

Observations: My body temperature was on the low side on the first measurement (it would have been a good idea to have taken an initial measurement before having gone out, in addition to blood glucose).

At 7:30 there’s already a significant jump in body temperature, back into the lower end of the normal range. Blood glucose shows a modest spike upwards.

At 8:00 body temperature has gone down a bit. I’m thinking there may be some measurement error with this older thermometer. There’s no reason it should have gone down as I was indoors the whole time (though there’s always some variability in readings). Blood glucose has already gone back down, the increase was very short lived. Normally I would expect a higher and longer lasting increase in blood glucose.

Thoughts:  This experiment was really quite impromptu. When I originally went out for the day I had no plans to measure anything. It was only when I was on my way home that I decided that it might be interesting to look at what would happen (hence there were no initial measurements taken earlier in the day).

Conclusions (if any): Is the ability to quickly metabolize the ingested sugars related solely to the level of physical activity, or can some of it be attributed to the cold weather as well (since energy must be utilized by the body to maintain normal body temperature). I don’t think I can say conclusively based on one instance, and it would be good to conduct an equivalent experiment in warm weather as well (though the activity level can never be exactly duplicated). It’s certainly plausible that the moderate blood glucose response was partly due to the cold.