Muscle cramps while running

Question
I recently ran (and finished!) the Houston Marathon.  During training (i.e. 18 & 21 miles) I had no problem with muscle cramps.  At about mile 14 in the marathon both of my quads cramped severly.  What happened and why on race day.  The only change to my rutine was eliminating sodas the week before and taking potassium/magnesium supplipents to build up for the 26 miles.  Any clues?

Thanks,
Matt

Answer
Dear Matt,

Self-administration of potassium/magnesium supplements may have upset the natural balance of the minerals in your body and very easily caused you to cramp. The body maintains an internal equilibrium and when you affect this balance you are asking for problems. Besides, you should never change a routine so close to any race. Don't make the same mistake twice. A number of years ago, a seasoned triathlete took potassium supplements on the Houston race course and died within a half mile of the finish. I know personally since I live in Houston and run this race every year.

Be grateful that your calamity was only cramping. Be careful in the future.

I hope I have been of some assistance.

Dr. Christopher Rampacek