It’s not just the 10,000 steps but – shocker – how fast you do them.
A fresh arrival in what we at TMR call the NSS files.
We’ve all heard of the 10,000-steps-a-day rule, and most of us have also heard the gentle debunking: it was made up by some guy in Japan in the 60s because it’s a nice round number but it has no real evidence behind it. This recent study found the effect plateaus somewhere around 7000 steps a day.
Well, two studies by the same lead authors in no less a journal than JAMA have at last backed up the wisdom of striving for your 10,000 steps, both for the avoidance of dementia and for the reduction of CVD, cancer and all-cause mortality.
Only they’ve added the not-at-all-surprising corollary that speed counts, too.
The researchers analysed the accelerometer data of nearly 80,000 people aged 40-79 from the UK Biobank, and linked it with mortality, hospitalisation and cancer and CVD diagnosis data seven years later. (“Cancer” was a composite of 13 forms linked to low physical activity: bladder, breast, colon, endometrial, oesophageal adenocarcinoma, gastric cardia, head and neck, kidney, liver, lung, myeloid leukemia, myeloma, and rectal.) They excluded anyone who experienced an incident of interest within two years of the study.
The team found an inverse dose-response relationship between number of steps walked per day (using a machine-learning algorithm that separated walking from other kinds of steps) and all-cause, cancer and CVD mortality.
The association held up all the way to about 10,000 steps a day, after which it became weaker. In any case, only about 20% of their sample actually achieved anything like 10,000 steps a day. There was no minimum step threshold for benefit.
The higher the peak-30 cadence – a measure of intensity of walking pace that reflects the walker’s “natural best effort” – the lower the mortality risks.
They also found inverse associations between both step count and peak-30 cadence and cancer and CVD incidence. This included “incidental” steps, not just those in a workout kind of context.
In the dementia study, which the authors say is the first of its kind, they used the same accelerometer dataset and looked for dementia incidence in primary care records or cause of hospitalisation or death. They found 10,000 steps a day to be the optimal “dose” for the avoidance of incident dementia, and even the minimum useful dose of about 4000 steps per day was associated with 25% lower incident dementia. Again, they excluded anyone with a diagnosis within two years of the measured steps, and it made no difference to the overall finding.
Intensity of steps strengthened the association.
As someone who schlepps about 5km a day to and from work at TMR Towers, but rarely cracks over 8000 steps, it’s nice to know death is a slowcoach.
If you have a way to outfox the Grim Reaper, let penny@medicalrepublic.com.au know about it.
