The numbers used to assess health are not helpful

Friday, July 12th, 2019

The numbers used to assess health are, for the most part, not helpful, but other, simpler metrics are:

The speed at which you walk, for example, can be eerily predictive of health status. In a study of nearly 35,000 people aged 65 years or older in the Journal of the American Medical Association, those who walked at about 2.6 feet per second over a short distance — which would amount to a mile in about 33 minutes — were likely to hit their average life expectancy. With every speed increase of around 4 inches per second, the chance of dying in the next decade fell by about 12 percent. (Whenever I think about this study, I start walking faster.)

Walking speed isn’t unique. Studies of simple predictors of longevity like these come out every couple of years, building up a cadre of what could be called alternative vital signs. In 2018, a study of half a million middle-aged people found that lung cancer, heart disease, and all-cause mortality were well predicted by the strength of a person’s grip.

Yes, how hard you can squeeze a grip meter. This was a better predictor of mortality than blood pressure or overall physical activity. A prior study found that grip strength among people in their 80s predicted the likelihood of making it past 100. Even more impressive, grip strength had good predictive ability in a study among 18-year-olds in the Swedish military on cardiovascular death 25 years later.

Another study made headlines earlier this year for declaring that push-up abilities could predict heart disease. Stefanos Kales, a professor at Harvard Medical School, noticed that the leading cause of death of firefighters on duty was not smoke inhalation, burns, or trauma, but sudden cardiac death. This is usually caused by coronary-artery disease. Even in this high-risk profession, people are most likely to die of the same thing as everyone else.

Still, the profession needed effective screening tests to define fitness for duty. Since firefighters are generally physically fit people, Kales’s lab looked at push-ups. He found that they were an even better predictor of cardiovascular disease than a submaximal treadmill test. “The results show a strong association between push-up capacity and decreased risk of subsequent cardiovascular disease,” Kales says.

You would think the drive to move to these new metrics would come from their effectiveness and efficiency:

This is driven in part by the Americans With Disabilities Act, which mandates that people not be discriminated against in occupational settings based on BMI or age.

This estimate caught my eye:

Granted, Joyner and other experts I heard from estimated that the number of Americans who can do a single push-up is likely only about 20 or 30 percent.


  1. Graham says:

    I am going to try that tonight. I assume I can do one.

    I am prepared to be surprised.

  2. Isegoria says:

    Graham, take a look at Mangan’s site.

  3. Harper's Notes says:

    What I have lost in walking less hurriedly I have more than made up in biking more furiously.

  4. Buckethead says:

    There are a lot of lard-asses out there, to be sure. And I’m regularly horrified when I happen to pass kids waiting for the bus. But even still, I’m shocked at that estimate — at best one in three, more likely one in five is all that can do even one push up?

    I’ve just turned 50, and I work out at best 2-3 times a month, and I smoke… the only thing going for me is the residual effects of manual labor from 30 years ago and a good diet. And I can do 15-20 pushups without killing myself.

    If the very low level of effort I’ve put into my health puts me ahead of 90% of the current population, that’s actually pretty scary.

  5. Mike in Boston says:

    When I glance at Figure 1 of the study I recall, it seems like there’s not much difference between being able to do twentysomething push-ups and thirtysomething push-ups, but that you really ought to shoot for 40. Alas, I seem to be stuck in the 22-25 range.

  6. Adar says:

    1. Single best indicator of a persons health the strength of your legs. Single best indicator of leg strength the standing long jump. Used by the Soviets to evaluate potential recruits for their special operations units.

    2. Single best manner to attain physical fitness weight loaded walking. Starting with a small amount of weight, walk longer distances faster and then add in a very slow and gradual manner more weight. As determined by Israeli military.

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