Gliding Balancing Act

As a  diabetic, balancing my blood sugar during races is critical for a good performance.  This is a difficult task given the numerous factors that can affect glucose in the blood stream.  For this post I am only going to focus on one such factor. .. terrain.

Through extensive testing I have learned that when I am in an anaerobic state my glucose rises significantly.  When I am in an aerobic state my glucose drops.  The rate that it drops increases with the intenisty of the effort.  I am at peak sugar burning mode at threshold.  Once my heartrate climbs into level 4 and level 5 territory my glucose suddenly begins to rise.

In a normal ski race I am constantly bouncing between a threshold effort and maximal effort.  My heartrate peaks at the top of a hill and slows as I go down the other side.  Thus my glucose levels rise and fall throughout the race until I put in a final anaerobic surge over the last few kilometers of a race.   A normal glucose level for a non-diabetic ranges from 70-140 during a race.  At below 70 a racer would be experiencing a “bonk.”  So it is important that I do not use too much insulin during a race.  However it is just as important that I do not use too little insulin.  My lactate level starts to rise unnaturally when my sugar reaches a level of 240 or more.  The margin for error is small, but thanks to testing on the Center of Excellence treadmill and many races and timetrials I have developed an inuslin dosing strategy that generally gives me a glucose level of 160 at the finish of a 15k race.

There are two types of insulin dosing, basal and bolus.   Insulin is delivered in measurements called units.  A basal insulin is a constant drip that is delivered into my bloodstream 24 hours a day by a mechanical box called an insulin pump.  The pump I use is called an OmniPod.  The bolus insulin is also delivered by the pump and is given at meal times or at any time a significant amount of carb is consumed.  I progam the pump and override the program when need be.  It is not an automated devise.

My basal rate depends on many different factors that I am not going to go into in this article, but for reference lets assume  that I am using my most commom basal dose of .7 units per hour in the days leading up to a ski race.  My pre-race dosing strategybegins 1.5 hours before the start.  At this point I double my normal basal insulin dose to 1.5 units per hour.  Twenty minutes before the start I bring the basal rate up to 5 units per hour.  I keep the basal rate at 5 units per hour until the completion of the race.

Yesterday’s Race to the Castle on Whiteface and other hill-climb timetrials present a different challenge for me.  Because there is no significant terrain variation there is no place to recover.  I am in an anaerobic state for over 50% of the race.  Thus my bloodsugar constantly rises unless I take even more insulin than in a conventional race.  During yesterday’s race my non-racing basal rate was .5 units per hour.  During the race I increased my basal rate to 7 units per hour and I still finished the race witha a relatively high glucose level of 204.  I have not documented any ill affects from racing at this glucose level but there is definately room for improvement in my controlm durin hill climbs.

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