The ability to go easily from standing to sitting and from sitting to standing has a good correlation with all-causes mortality

The test was a simple assessment of the subjects' ability to sit and then rise unaided from the floor. The assessment was performed in 2002 adults of both sexes and with ages ranging from 51 to 80 years. The subjects were followed-up from the date of the baseline test until the date of death or 31 October 2011, a median follow-up of 6.3 years.

Before starting the test, they were told: "Without worrying about the speed of movement, try to sit and then to rise from the floor, using the minimum support that you believe is needed."

As might be predicted, I'm putting in a little work on improving my ability at the test-- I have no idea whether this an example of Goodhart's Law.