Monday, December 17, 2007

Post-Swim Highs

Last year, I had some trouble with high BG's coming out of the swim at races and also at practices. At first I attributed it to being off the pump for an hour or more and under-dosing beforehand. But it still happened when I started wearing my pump while swimming. It doesn't happen all the time, though, so I'd really like to figure out what is going on and get a better sense for how consistent the pattern is (and how to deal with it).

Here's today's data:
  • 5:10 AM 136
  • 5:40 AM 155
  • 5:45 AM start swimming--workout included 3 fast 300's and 1 fast 600, moderately intense pace with some easier, shorter sets
  • 7:00 AM stop swimming
  • 7:45 AM 211
I didn't eat anything this morning before or during the swim, and kept my basal at its regular rate of 0.575 U/hr. My pump was low on insulin (7 U when I got up); so perhaps the rise in BG was primarily due to that, especially since my BG was rising before I got in the pool. I've suspected that, when my pump is almost empty, the delivery is less accurate due to the accumulating air bubbles in the cartridge. The workout was fairly intense and sustained, which usually causes a rise in my BGs. Next time if my BG is rising, I will try giving a tiny bolus (0.1 U) and see what happens. I should also reincorporate eating beforehand, to improve the quality of my workout and to practice race conditions. (I'm trying to lose a few pounds and have been cutting out some of my training calories lately.)


Wingman said...

I've noticed that a spike after a workout will often go down about a 1/2 hour after the spike. I think swiming is more difficult because of the climate in the water and our bodies reaction to it - most likely producing more cortisol and speeding things up to keep our core temperatures warm.

Brett said...

I am not a doctor, nor do I pretend to be.

I have a 5 1/2 year old daughter who was diagnosed with Type 1 Diabetes at 16 months of age. I have noticed that during times when she is sick, it takes almost double the insulin to keep her blood sugars down.

Everytime she goes high when sick we think she has a bad pumpsite, only to see her sugars come back down when we ramp up the amount of insulin we give her.

I think various physiological changes in the body cause this - when she is sick, do antibodies or something like that become more active and supress the effect of the insulin?

I bet the same thing happens here - is it the cold water contracting the blood vessels at the surface so that they aren't getting insulin circulation as well?

Is it adrenalin because of the above and the level of exercise?

I just did a few searches, and here is an interesting finds: - this one is even better..."stress and adrenalin can raise your blood sugar" and "If they exercise and don't have much insulin on board, then their sugars can go very high, and if they have lots of insulin on board and exercise strenuously without enough food, they can have severe low blood sugar reactions."

Hope that helps!