Thanks for all the replies everyone. I still haven't noticed any discomfort, and I think I may have noticed a slight improvement in the way my knees feel. I've only been riding a couple months, and some I expect some soreness now and again, but after the last 2 days with 25+ miles each day I don't feel any soreness or weakness in my legs when somedays it would feel almost like shin-splints in my knees. I might even go a touch higher, just to see what I can get out of it.