Originally Posted by
Doge
Pretty hard to know.
For Z4+ the whole weights and rowing seem to work very well for cycling. As posted above, I'm more concerned about endurance > 70 mile stuff, back to back days. I don't know of any shortcuts other than big miles and it is very difficult to get those miles (as everyone here knows).
Isn't that the entire reason that intervals are popular?
I doubt you have to do those kinds of rides often to get the training effect you're looking for.