Why did ‘marathon runners’ in this lab experiment  become more anxious and neurotic than the nonrunners? Presumably because of the volume of their running.

The apparent implication of that finding — that too much running makes an animal a nervous wreck — might seem disconcerting. But as this study, published in the journal Hippocampus, and additional new research makes clear, a great deal still needs to be understood about just how exercise affects mood.

••• For original NEW YORK TIMES article here

2 thoughts on “Does Exercise Really Boost Your Mood?

  1. If you read the whole article, you’ll see that the “marathon runners” referred to in the question above are actually mice, and that the”anxious and neurotic” behavior shown by the mice that ran the most may actually be a healthy adaptation not shown by the sedentary mice. I am not a behavioral scientist or knowledgable about neuroscience, but surely the behavior of the running mice might mean that a lot of running – something mice might only do if they are in a situation where there is inadequate food or dangerous predators – leads to more neurogenesis, meaning that when they are put into a new situation they respond more appropriately than their sedentary lab-mates, i.e., by freezing (so they are harder to spot by predators) or by running into corners (to hide from predators). It is possible that the behavior of the non-running mice, when put into novel situations, is highly maladaptive.

    We don’t know what this research means, because we are not given enough information. What we can tell is that the research on mice – inadquately interpreted in the NYT article – does not support a conclusion that exercise for humans doesn’t elevate one’s mood, which is the implication of the headline. If human brains respond to high levels of exercise the way the mouse brains did, by producing many more new neurons that were less excitable than the previously existing ones, perhaps this means that people who exercise a lot are likely to be better able to adapt calmly to new situations, while sedentary people, relying on their old overly excitable neurons, are likely to respond less appropriately or not at all.

    In any case, the question that heads up this column (“Why did marathon runners in this experiment become more anxious and neurotic than the nonrunners? Presumably because of the volume of their running.”) appears to be misleading in at least a couple of different ways. Read the article carefully and see if you don’t agree.

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