Leg pain or fatigue?

I get this burning/tingling sensation in my leg muscle particularly in my thighs whenever I perform a mildy intense activity e.g. walking up a flight of stairs. This burning or tingling sensation comes on really quickly and is really starting to annoy me I have had it for a while. I recently changed my running shoes to a pair that provided more support with a lot of cushioning. I run more on treadmills than I do on outside ground. I don't think its to do with with the lack strength I have in my thigh muscle because comments have been made to be about strong my thighs look. I don't know whether or not it is muscle fatigue or a serious injury and I don't know what to do about it, should I stop training completely? Is there any remedy that would help get rid of the burning or tingling sensation? Any help or advice at all on what I should do or what my condition is would be greatly appreciated!
Thank YOU

It's not one I've heard of (though I'm an amateur!) - Given the lack of response, it seems I'm not alone. Think it's one to mention to the doc or physio.  Hope you get to the bottom of it.

I'm no expert either but I have had that sensation also. It was when I was overtraining and my legs would burn when I went upstairs, mainly in the thigh area. Now I have cut back and am following a more sensible training routine i.e. more structured with more rest days, I dont suffer as much and when it does come on after going up the stairs the sensation goes away after a few seconds. What sort of mileage are you doing, how long have you been running for ? 

How many more rest days are you taking then, carterusm as what you have described seems to be exactly what I have. I have made an appointment with a physio. I have been running for about 2 years now and I am not setting targets e.g. I do not have specific race I am building up to like a marathon I run to increase my fitness level so that by the end of each month I am performing a fitness test to prove that my fitness has increased so in a sense that is what I am working towards. I am doing at the moment between 15 and 20 miles a week. I have cut down on the amount of training I am doing but I still feel like I have to train to stop my fitness from plummiting. What would be best to continue training or cut it out all together? Thanks guys