I know I've been here before, but The Times is at it again. In today's issue (25/01/23) we read: "Sharpen your mind with six minutes of hard exercise a day". Six minutes? – I could manage that, you think. So you start to read, and plough through six paragraphs detailing the numbers of patients involved and the testing they were subjected to (no mention of what they classed as 'hard exercise', but let's ignore that). It's only in the penultimate paragraph that we get the actual results of the exercise on cognitive functioning.
And what do we see? – forgetful old codgers suddenly completing the Times crossword and entering for Mastermind? No. There was an increase in cognitive functioning of 1.27%. Even using the most reliable testing system available that sort of difference would almost certainly fall within the error limits of the experimental methodology, but these tests included assessments of 'ability to plan, focus, multitask and remember instructions', which are unlikely to be particularly rigorous and reproducible. You don't have to be a research scientist or science editor to know that an increase of that size is unlikely to be statistically significant, and even more unlikely to be perceptible to the test subjects.
I haven't had the opportunity to see the actual data which led to these results, and that's the problem with all press reports on scientific research. They invariably present percentage changes with no indication of the limitations of the methods used. I'd be willing to bet that these results would be compatible with the 'null hypothesis'; namely that the exercise had zero effect on cognitive function. Which all boils down to irresponsible reporting in my book – the headline would certainly mislead anyone not reading to the end of the piece, but of course the fact is that the article shouldn't have been there at all, it's simply not newsworthy.
And before I go, there's another thing to note in this article. It's that figure of 1.27% (and the 1.31% quoted as the improvement in 'cognition ranking', whatever that is). Those are very precise figures, which imply a corresponding degree of precision in the methodology which, as I said above, is unlikely to be realistic. This is done to give an impression of accuracy, but precision and accuracy are two very different things. Let me tell you a story. When I was a wet-behind-the-ears junior RAF Medical Officer, I was asked to perform the annual medical on a very, very, senior officer. This was at a time when limits for safe drinking had first been suggested, and these had been incorporated into the medical exam. So I had to ask this imposing figure how much he drank in an average week. "Seventeen units" he answered, this being several units less than the proposed safe limit. "That's very precise, sir" I replied. "Yes doctor" he said, "very precise, but not necessarily very accurate".
The bottom line is that when it comes to exercising to preserve what remains of my cognitive functioning, I'll stick to walking the dog and gardening. And to keep coronary artery disease and ulcers at bay, I'll stop reading press reports of scientific research.