Early physical activity doesn’t just affect the muscles; it strongly influences bone characteristics as well. Unstructured childhood rough-and-tumble play being literally necessary for military-grade bone density is just the tip of the iceberg.

That the boys play Cowboys and Indians is a matter of national security.

It did make me want to go and get a dynamometer, though.

Less a marker of any individual’s mortality, and more just a marker of our slow transition into Eloi. Finally I’m a trend leader.

Now, if you want to use grip strength to predict mortality, then you’d compare your subject to the grip strengths of his age-cohorts, not to age-cohorts of a few decades ago. Lifestyle changes, as Wang Wei Lin points out.

I wonder whether you could use some kind of small-motor-skill measure on women.

I wonder whether you could use some kind of get-out-of-chair measure on both sexes. Like how long it takes to get out of a chair, go around it, and sit down again. 3 times. Make the chair somewhat unstable. On rollers and leaning back, for instance. And the person in socks. On a slippery floor. … … … Um. 15 seconds.