My max is 160, and I notice little improvements in shifting the load from heart to muscle. I used to max out going up Torrey Pines at 4-5, now do it at 7-8 at 145-150. I am setting PRs on hills, but dropping weight is a big factor there. My first run up that hill (since the '70's) was at 240#. the most recent was at 220ish.