I was a little surprised when I heard the news on the radio this morning and heard that a new study had been published allegedly showing that millions of middle aged adults are so inactive that they don’t even walk for 10 minutes each month. The story has been widely covered in the media, for example here, here, and here.
The specific claim is that 41% of adults aged 40 to 60 in England, or about 6 million people, do not walk for 10 minutes in one go at a brisk pace at least once a month, based on a survey by Public Health England (PHE). I tracked down the source of this claim to this report on the PHE website.
I found that hard to believe. Walking for just 10 minutes a month is a pretty low bar. Can it really be true that 41% of middle aged adults don’t even manage that much?
Well, if it is, which I seriously doubt, then the statistic is at best highly misleading. The same survey tells us that less than 20% of the same sample of adults were physically inactive, where physical activity is defined as “participating in less than 30 minutes of moderate intensity physical activity per week”. Here is the table from the report about physical activity:
So we have about 6 million people doing less than 10 minutes of walking per month, but only 3 million people doing less than 30 minutes of moderate intensity physical activity per week. So somehow, there must be 3 million people who are doing at least 30 minutes of physical activity per week while simultaneously walking for less than 10 minutes per month.
I suppose that’s possible. Maybe those people cycle a lot, or perhaps drive to the gym and have a good old workout and then drive home again. But it seems unlikely.
And even if it’s true, the headline figure that 41% of middle aged adults are doing so little exercise that they don’t even manage 10 minutes of walking a month is grossly misleading. Because in fact over 80% of middle aged adults are exercising for at least 30 minutes per week.
I notice that the report on the PHE website doesn’t link to the precise questions asked in the survey. I am always sceptical of any survey results that aren’t accompanied by a detailed description of the survey methods, including specifying the precise questions asked, and this example only serves to remind me of the importance of maintaining that scepticism.
The news coverage focuses on the “41% walk for less than 10 minutes per month” figure and not on the far less alarming figure that less than 20% exercise for less than 30 minutes per week. The 41% figure is also presented first on the PHE website, and I’m guessing, given the similarity of stories in the media, that that was the figure they emphasised in their press release.
I find it disappointing that a body like PHE is prioritising newsworthiness over honest science.