Run, road or trail . . .
I'm relatively new to running, and spent my initial months pounding the pavements, but then came across a slight off road element in an early race, and struggled. Since then I've generally avoided the roads and been off road running throught the local trails, and what a revelation. Clean air, hills and wildlife. However, although I feel my general stamina has improved, and I'm able to deal with all terrains, I'm not sure whether my overall speed will have been affected. Racing on the weekend at London, which is flat and concrete / tarmac, will I notice a difference?