I got a Fitbit for my birthday. Among the many things it tracks is the number of occasions per day when I climb the stairs. Stair-climbing is apparently a major contributor to cardiac fitness among sedentary people, so I do it frequently -- at least 10 times per day.

I believe that Fitbit has it wrong, however; going up (as most of us know by now) is actually the easy part. The big trick is coming down gracefully and safely, without teetering, toppling, skidding or otherwise losing one's footing and, consequently, doing a head-first dive or a bottom-first bumpy slide to the bottom. For me, the hindrance is arthritis in the knees, ankles and feet that stiffens the joints of my personal undercarriage. The first descent of the day is always a crap-shoot: will the ankles flex today, or not?

The housework task that generates the most fitness benefit for me is vacuum cleaning. It combines weight-lifting with upper-body and core flexion and several interesting balance challenges, of which the first is moving the vacuum cleaner from the bedroom closet down the stairs to the sitting room rug without bashing the plaster.

Fun times in retirement. What larks, eh?