Thanks wuverley and bfergie, yes with hindsight I have realised I have maybe got to hung up on keeping to a formal training plan with all the intervals, lactice thresholds, etc.

It is the desire for added benefit or the 'something for nothing' mentality!

Although the China bike ride is my main aim I do wish however longer term to do some sort of competitive cycling. But best just to get the challenge done first i guess and then go on to more formal training next year.