My training regimen consists of alternating ride days with running days. I run on recovery days. What I'm wondering is how well does running conditioning translate to on-the-bike conditioning. For example, if I did a few lactic threshold intervals (say, 90% max HR) on my runs to what extent would that benefit my lactic threshold on the bike? It seems like there would be a worthwhile cardiovascular benefit. The other thing I wonder about is recovery. Most talk about recovery seems to deal with muscular recovery (i.e. the leg muscles). Is there a similar requirement for heart/lungs?