Running

I have access to treadmills, I quite like the idea of varying my training so I'm not always on the road but I'm not sure of the validity I running on a treadmill and the way that my trnsfer to running on the black stuff.

Appologies, I don't have a very well informed/technical answer as I haven't run on a treadmill since I started running (semi)seriously, but maybe that tells me something. I know treadmills are supposed to replicate running but I find that on a treadmill you can basically put all your effort into hopping up and down while trying not to loose your footing on the rolling mat. You don't need to drive yourself forward on a treadmill like you do on the road, and I've never thought of it as an adequate substitute for running outside. Personally I can't see why you'd want to either, getting out into the countryside is what running is all about for me - I can't imagine anything worse than being stuck in a gym.