Sewer Tunnel Laborers

Is Hard Labor Good for Your Health?

Scientists and health reporters love a paradox. It earns clicks and ad dollars. It garners citations and visibility. So Pieter Coenen and colleagues are getting attention this week with a claim that they’ve found a physical activity paradox. In their analysis, they find that hard labor – high levels of physical activity at work – correlates with 18% higher risk of death.

But Isn’t Sitting the New Smoking?

For years now, we’ve been hearing that sedentary work patterns are killing us. Too many jobs have us spending too much time stuck in a chair and glued to a screen. And compared to more active work patterns, sedentary work carries an added risk of premature death.

So which is it? Should we be worried about too much physical activity at work? Or too little?

Choosing a Narrow Question to Ask

Because Coenen et al were looking for a paradox, they asked a very narrow question. What’s the relative risk of a job with high levels of physical activity, compared to one with low (but not sedentary) levels?

Thus it tells us nothing about how much physical activity at work is just right. Comparisons to moderately active and sedentary work patterns just weren’t part of their study. It makes for a more sensational press release – but not a more informative one.

Too Much of a Good Thing

It shouldn’t surprise us that hard labor might be hard on a person’s prospects for a long and healthy life. There’s a reason why developed economies are emphasizing work that is less physically demanding. Along with physical demands come physical hazards.

The truth is that physical activity at work has been declining for many years. Too little physical activity – not too much – makes many jobs unhealthy.

Physical activity, whether it’s at work or at leisure is clearly beneficial – up to a point. But beyond a certain point, a reverse J-curve effect kicks in. Too much of a good thing becomes a bad thing. It starts to erase the health benefits. That might come with an obsessive and unhealthy pattern of exercise. Or it might come with a physically punishing job.

Some of the headlines from this week’s study suggest physical activity at work is bad for you. That’s irresponsible, because the study proves no such thing. First of all, it’s documenting an association – not cause and effect. It could easily be that other factors associated with physically demanding jobs are responsible for this finding.

But more important, this study asks a very narrow question. It doesn’t support a broad conclusion about all physical activity at work.

Click here for the study, here for the press release, and here for some perspective on how much physical activity is too much.

Sewer Tunnel Laborers, photograph © Seattle Municipal Archives / flickr

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May 16, 2018

One Response to “Is Hard Labor Good for Your Health?”

  1. May 20, 2018 at 10:09 am, John DiTraglia said:

    it’s also been shown i think that obesity is not less common among laborers than desk jobbers.