That is a lot, at least to me. I have to drive at leat 45 min to ride, so I usually ride twice a week, 2 hours a session, usually pretty hard because we have to plan to get there.

Then I cross train by trail running two days a week, and I lift twice a week to strengthen upper and lower body.

I am no expert, but that seems like a lot. Mt biking is tough on the old quaddies if you are doing lots of climbing.