@OmSigDAVID,
Hey David
I'm kinda hesitant to say this, and I am sure you are wise enough to check with your GP ..... but salt... increase salt intake, especially if you getting dehydrated.
<I was an athlete, leg cramps after training - was advised to increase salt levels - but that was an eon or three ago and a lot of folk are very anti salt
>
leg stretching is very important and will help!