I've just started to road run after getting very bored on the running machines in the gym, and think its fab. The country roads around home are rather hilly, but I can comfortably run for about an hour, and cover about 10K. However, I've started to get twinges in my knees. I have got a good pair of running shoes and don't hurt anywhere else! My knees feel as if they are 'cold'. Unfortunately I can't escape the hills but would love any tips.