[Scott Johnston]

Josh:

Yes, I would recommend adding in sustained Z3 on longer runs.  Dip your toe into this cautiously as you need to see how that added stress combines with what you are already doing.  Start with 20min during one of your normal 1 hour runs.  Increasing Z3 volume in these shorter runs will be safer.  It may well be that after a few weeks of that you will feel confident to bump up Z3 volume in a couple of runs and even  during a longer run.  This will be some very specific training if your goal is trail running.

I hope this helps.

Scott