Cycling, running and cramp

If you ever listen to the excellent Radio 4 programme Inside Health, presented by Dr Mark Porter MBE, you might know he sometimes invites listeners to get in touch with health queries.  Here's mine.....

Dear Dr Mark,

From time to time I get bouts of cramp, mainly in my legs and feet.  When I get cramp it is often at night and a muscle seems to go into a kind of stiff spasm and be very taught.  I can tell you, it can be dramatic waking up at night with an agonising pain in either my left or right leg.  It scares the living daylights out of my wife who will often wake up as well, very startled at me leaping and hopping around the bedroom.  

It seems to generally affect one muscle at a time, either in the upper or lower part of my leg.  It's the same with my feet but that's not quite so painful as I guess the muscles are smaller.

While I get cramp mostly at night, it sometimes happens when I cycle and believe me, this is a little disconcerting when you have both feet clipped into the pedals.  Like many other cyclists, I use a clipless pedal where your cycling shoes are locked to the pedal.  Releasing your feet is done by twisting the heel outwards and then the shoe springs out.

Me, my health

I am in my mid fifties and have no health issues.  I'm pretty active and fit with running (I average over 20 miles each week) and cycling.  My BMI is 22.5 and I'm in pretty good shape.  I'm tee total, don't smoke and I'm a vegetarian.  I reckon my diet is pretty good generally; I especially eat lots of fruit (as many different kinds as I can over the course of a week).

My own Doctor

Every year I make sure I get a health check covering the usual things such as blood pressure, cholesterol, liver and kidney function etc.  These are all fine and my Doctor says "well done, keep it up".

I did mention the issue of cramp to my Doctor.  She said that she wasn't very knowledgeable about it and flicked through my notes and said there was no obvious reason.  She felt behind my knees and then held my feet in her hands and commented they were colder than she expected, although it was a chilly day.  Other than that there was nothing to say or do apart from "I could suggest you give up running any cycling but I doubt if you'd think that was a good idea!".

Electrolytes

Some people suggest sports drinks to be a solution and yet there are many different types around.  I have tried taking some electrolyte drinks which might help but I cannot be sure, there's no regular pattern.

Any suggestions?  

Goes without saying I'm hoping you can cover this on Inside Health, I'm happy to be interviewed or provide some further information if that would be helpful.

Links:
Radio 4 Inside Health
Electrolyte drinks - do we need them?