Wednesday, 4 February 2015

Is strenuous running bad for you or are BBC journalists getting lazy?

Yesterday the BBC posted this article with the title "Too much jogging 'as bad as no exercise at all".

This sensational sounding article is bound to attract interest and give a lot of people the impression that regular strenuous running is bad for you and you would be better off on the couch.

Now most of us would expect that Paula Radcliff has a better likelihood of growing old healthily than say Waynetta Slob. But this article says otherwise.

You would expect that the BBC journalist had taken a good look at the subject before writing such an article.

The article refers to a study published in the Journal of the American College of Cardiology. Which apparently says that People who jogged more intensively - particularly those who jogged more than three times a week or at a pace of more than 7mph - were as likely to die as those who did no exercise.  This is a surprising finding.

The article they refer to is here;  In the public synopsis it says: "Light and moderate joggers have lower mortality than sedentary non-joggers, whereas strenuous joggers have a mortality rate not statistically different from that of the sedentary group." 

This statement is simply not supported by the data shown. The graph below, which forms the central illustration of the report, shows clearly that over a quarter of the non-joggers died, and only one 18th of the strenuous joggers died; further to that the total of those was just 2, this is not a statistically reliable number from such a small sample group (the data is not adjusted for freek accidents).  The one thing we do see is the glaring fact that far more sedentary people died than those who jogged. 

If you listen to the audio commentary they refer to the sample size and say that more data is required. So you have to wonder why a responsible journalist would feel happy to draw such a dramatic conclusion from the available information.

It’s not hard to find further research on the same web site that clearly supports the generally held view that regular running is beneficial. Here is an example from a much  larger study of 55,1367 adults.

This graph suggests that running at about 7.5 mph up to 5 times per week is the best thing you can do for your health out of the reported choices.

Come on BBC, you can do better than this!


  1. Hi Malcolm, great post. I had a text with a link to this BBC report from a gloating, non-running friend suggesting that I hang up my running shoes or at least slow down bit. I was delighted to be able to reply with a link to your blog and to tell him to get off his arse!
    With the news this week that the decision to promote a low fat in the UK was based on very unreliable evidence, I do feel that the tide is turning on LCHF - it just feels painfully slow. Keep up the good work.