It seems like every winter, I have this problem and it doesn't go away for a month. Both of my quads will cramp severely if I try to walk down stairs, even just walking at a steady pace it will happen. I stop, stretch, start to walk slowly again and then repeat the routine because they will cramp again after another thirty steps or so.

I may be wrong but I'm pretty sure that the cramps are triggered by periods of inactivity. I work out regularly, and this last time I took a week off because I had a ton of work to do; next time I try to break into a light jog, they go nuts again. I've tried eating lots of potassium, drinking lots of water.. not really any improvement. Any suggestions? I don't know whether to heat the muscle, ice it, both...

In response to the answer given by Mark H:

It has happened in the summer before as well, but it was after I finished a 6-week bike trip so I put that down to overuse.

I should note that they don't cramp randomly; after doing so searching on google I see that some people have cramps that come on for no reason and without warning. Mine are very much predicated by some usage of the muscle, even if it's as little as walking down five steps. I'm as ginger as I can be with myself while I have this problem, and when it goes away it doesn't come back for a long time.. but while it lasts, it's a real pain in the *** because it makes walking medium distances an impossibility.

the cold weather definitely has something to do with it as well, which i suppose is not very surprising.

thanks for your help..