Exercise is associated with mortality benefits but simply expending energy through any activity in an individual's free-living environment may confer survival advantages.
--Todd Manini, PhD et al, JAMA, July 12, 2006

Why am I glad my son dribbled lemonade across the kitchen floor? Three words--free-living energy, as in my energy spent cleaning up his sticky mess (he was long gone for the evening). While some energy expenditures are more fun than others--say dancing compared to mopping--expending energy at any activity improves survival, and now we've got the scientific proof.

Researchers at the National Institute of Aging studied a grip of high-functioning old folks over six years to see who made it to the end of the study in the upright position as a function of how generally active they were through the years. They did not, however, depend on those unreliable old memories to determine who moved and who didn't. They fed the seniors 'heavy water' where extra neutrons are somehow added to the hydrogen and oxygen atoms. The heavy oxygen goes in as water and comes out as CO2 at a rate dependent on the amount of heavy breathing the oldsters do while house-cleaning etc.

The group of participants in the lowest one-third of energy spent per day were twice as likely to be carried out of the study feet first compared to those in the highest one-third.

So perhaps I will not only survive Mike's adolescence, I will thrive as a result of it. Pacing the floor and wringing the hands counts as activity, right?