Thanks - helpful response. I'm kind of thinking through all these questions now. Heres a bit more quick background:

Basic issue is that I'm heavy ( not the bike - its a Cervelo P3SL, I can't blame it in the slightest) and don't have enough power. Although much lighter than I was 12 months ago, I'm still just over 100kg. THis is largely because I am built like a football player but nevertheless, my goal is around 90-95 so still plenty of extra being carried at this point.

Another issue might be how I pedal. Strangely, my quads & bum never really get tired, my calves do though. Perhaps I'm over-using my lower legs? I plan on spending some time with good cyclists and a coach to check if this area needs work. The weight which is an issue as above, should mean that I have lots of power with big legs but its not really the case . More time on the road might help smooth this out.

I have a powermeter on my windtrainer but have not really used it to its potential yet. Working on that next.

Olympic & sprint are really my ideal distance and will be the focus of the rest of my season. The swim is my strength and this can count for a lot in a short race. I plan to keep building speed and experience with these distances before looking at IM /70.3 somewhere down the track.

Just a last aside - by FTP do you mean Functional Threshold Pace? If not, what?

thnx