Stepping Behind Headline Statistics

“Four in ten middle-aged adults are failing to manage even one 10-minute brisk walk a month”

“Four out of every 10 forty- to sixty-year-olds take a brisk 10-minute walk less frequently than once a month”

These headlines shocked and bothered me. I wonder whether, when you hear or read them, your immediate reaction is the same as mine. I interpreted it to mean that 4 in 10 people are hardly moving in a month.  

But that didn’t seem to make sense to me. I therefore thought I would look into the data a bit further. This is an irresistible temptation for a forensic accountant, trained not to take numbers at face value!

I have a busy day so I didn’t spend as long as I would have liked but I did discover the following.

First, all the published data[1] is in age bands of 16-24, 25-34 etc ending with 65-74 and 75+. Therefore, I could not locate data for the band mentioned in the headlines of 40 to 60 years (I have asked for it though).

Secondly, I looked at the survey questionnaire[2]. The question series seemingly prompting the data used for the headline grabbing statistic was “We would now like to ask you some details about the activities you have done in the past 4 weeks….” And “For each activity that you have done, please answer these questions.  During the past 4 weeks, on how many days did you do the activity? How much time did you usually spend doing that activity on each day that you did the activity”. It therefore seemed to me to be entirely possible that if people, say, went for a run, a bike ride or a swim instead of a walk, they would be one of the 4 in 10, who I assumed from the headlines were hardly moving.

Interestingly, there is also data in the survey about level of activity/inactivity.  If you are inactive, this is defined as someone who does less than 30 minutes per week of moderate activity, which is defined as