Last week I did a lot of walking and moving of boxes, ranging between 10 and 40 pounds but mostly 30+. I feel a difference in my arms, 'cause it's not like you move the stuff once--Gotta lift each thing multiple times to get it to its final home. ;)
Moving offices is interesting--I had not even half a tote of stuff, so I was volunteered to help move some people who were out on vacation/disability. Some of these people had 50+ two- and three-inch binders of documentation that had to be moved, in addition to their boxes, computers, and mini-fridges.
This was in addition to throwing the Frisbee for the peanut for 15 minutes every two or three days--Better than once a week. ;) Doesn't do much for me, but it's doing wonders for her. :)