Thanks for the reply! I’m in no way trying to avoid long workouts. I routinely get out for long days in the mountains (4-6k elevation foot climbs of the volcanoesin OR). My issue is how actually about making my mid-week workouts longer. I can run for 1.5hrs but after that my knees start to hurt. If I run, I can do 10+ miles on rolling terrain or climb 1500 foot hills in Portland but then half the time is spent descending. However, while on the stairmaster, I can do a full 2 hours of all climbing (but not “against gravity”).
Anyway, I think that I just need more weight for ME. With a 45lb pack, the rate limiter is HR not leg strength, so I guess those workouts are base workouts. If I put 60 or so in the pack, I think my legs would be limited more ME.