In reply to petemeads:
> I was going to mention the American use of 'pickle juice' to stop cramp.
Yes, that's it. I tried apple vinegar. It didn't seem.very practical because the idea was to take a gulp as soon as you felt an attack in time yo stop it.
> During the last few years I have managed to get out on long mountain days more often, and become fitter, but got taken out of the Welsh 3000s by desperate cramps in both legs whilst descending Tryfan. 3 years later (ie last month) I got completely exhausted on a 24 mile/11,000 ft day with no sign of cramp either during or after.
Does that suggest there is something odd going on. You need to be at a certain level of fitness, but at that level can push as hard as you like. Level of fitness being the key rather than level of fatigue.
I'd pay a lot for a drug that would prevent cramp and so remove the horrible fear if it on every biggish day.