hey neil
due to work i dont get out half as much as i'd like, so compared to this lot im very unfit!
i started just doing what felt right - going for 15 minutes at first at what i'd reckon was about 70% of my capacity - kind of fast road cruising pace, with 3 minutes of warm up warm down on each end. it soons flys past and quickly turns into 20, then 25. ive started breaking things up now a bit more and introducing more hard sections and more quick spinning too.
its made a HUGE difference when i actually do get out on the bike.
HTH!
BC