November 16, 2019

Running can help you live longer. And more isn’t always better

Here we go again.  As usual, the researchers did not ask WHY people were in their various categories. In particular, who were the non-runners?  Many were probably not very well, and that would swing the overall averages for their category  -- so all we have here is a finding that people who were not very well had shorter lives -- how astounding is that?

All these correlational studies fall because of the basic statistical dictum that correlation is not causation.  So they will never deliver watertight conclusions. But that is not a counsel of despair.  By controlling for likely confounders (such as health, above) they can still deliver persuasive evidence on their question

But very few researchers make much of an attempt at controls. Income and social class are the big lacunae.  Both are of course politically sensitive so that is part of the reason for the gap but I think another one is laziness.  Once they have done enough to get into the journals they think they have done enough

But it is not enough.  Every study of the subject that I have ever seen shows poverty to be a big influence on health. So even in the present study that could be at work.  Jogging and other running exercise seem to be a mainly a middle class activity.  So the researchers below were probably contrasting poorer people with middle class people.  So all they showed was nothing more that what we have always known -- that the poor die younger.  Big deal!

Education is a reasonably easy datum to get and that is often controlled for and presented as evidence of demographic control -- but that is a very feeble attempt.  As a measure of social class, for instance, it overlooks the big role of subjective class

It is true that getting income and social class data is the hardest part of survey research.  But I nearly always got that in my research career so it just depends on how much you are invested in your research.  I really wanted to find out what is going on rather than just producing something that was "publishable".  And I got lots published anyway.


One major reason americans don’t get enough exercise is they feel they don’t have enough time. It can be difficult to squeeze in the 75 minutes of vigorous aerobic exercise per week that federal guidelines recommend; only about half of Americans do, according to the most recent numbers from the Centers for Disease Control and Prevention. But new research suggests people may be able to get life-lengthening benefits by running for far less time.

In a new analysis of 14 studies, researchers tracked deaths among more than 232,000 people from the U.S.,

Denmark, the U.K. and China over at least five years, and compared the findings with people’s self-reports about how much they ran. People who said they ran any amount were less likely to die during the follow-up than those who didn’t run at all. Runners were 27% less likely to die for any reason, compared with nonrunners, and had a 30% and 23% lower risk of dying from cardiovascular disease and cancer, respectively. This was true even for those who didn’t log a great deal of time. The analysis grouped people into clusters, with 50 minutes or less per week representing the group that ran the least—but still ran.

“Regardless of how much you run, you can expect such benefits,” says Zeljko Pedisic, associate professor at the Institute for Health and Sport at Victoria University in Australia, and one of the authors of the new analysis published in the British Journal of Sports Medicine ("Is running associated with a lower risk of all-cause, cardiovascular and cancer mortality, and is the more the better? A systematic review and meta-analysis")

The analysis is The latest to illustrate the benefits of running on the human body. “It’s what we evolved to do,” says Daniel Lieberman, a professor of human evolutionary biology at Harvard University (who was not involved in the new research). People may no longer chase down prey for their next meal, but running is still helping us survive: as leisure-time exercise, it keeps us healthy. “One of the best ways to avoid having to see a doctor,” Lieberman says, “is to stay physically active.”

The physical demands of running “affect just about every system of the body” in a beneficial way, Lieberman says. Take the cardiovascular system. Running forces it to adapt by “generating more capacity,” he says. “You grow more capillaries and small arteries, and that helps lower your blood pressure.” (High blood pressure is a major cause of health problems and death.) Running is good at guarding against cancer partly because it uses up blood sugar, starving the cancer cells that rely on it for fuel. And it protects you in other ways not necessarily measured in the latest research: by decreasing inflammation, for example, which is at the root of many diseases, and stimulating the production of a protein that improves brain health, Lieberman says. “Vigorous physical activity has been shown to be by far—with no close second—the best way to prevent Alzheimer’s,” he notes.

The good news for people who want the maximum longevity benefits—while spending the least amount of time slapping one foot in front of the other—is that running more than 50 minutes per week wasn’t linked to additional protections against dying. Neither were how often people ran and the pace they kept. As long as you’re running, more isn’t always better, especially given that the risk of injury increases with repetition.

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