A couple of years ago I did my best, and most irritating, time of 3:00:44 for a regular road marathon. I'm thinking that I'll might have a go at shaving 45 seconds off that time, but can't be bothered pounding the roads in order to achieve it.

I'd like to ask if anyone has successfully improved road race times without going near tarmac in the build up, whether you were at all scientific about it. I'm prepared to put the time in on the hills.

Any info anywhere as to how to compare fell logged miles vs road ones?