World Half Full
You don't need to do 10,000 steps a day
Clocking up 10,000 steps a day with a pedometer strapped to your leg or a smart phone or watch counting every move is supposed to be a simple way to keep ourselves healthy. But is it? Well, perhaps not. It turns out that for most of us whose physical activity is limited to walking, we need only accumulate around half that number a day to reduce, sometimes dramatically, our chances of dying young.
Writing in The New York Times, Gretchen Reynolds reports the goal of 10,000 steps a day for fitness’ sake is based on a fad invented by a Japanese watchmaker, hoping to capitalise on the interest in fitness in the wake of the 1964 Tokyo Olympics. The watchmaker mass-produced a pedometer with a name that, when written in Japanese characters, resembles a walking person; it also translated as “10,000-steps meter”. Somehow it took off.
Reynolds points to a 2019 study by Dr I-Min Lee, a professor of epidemiology at the Harvard T.H. Chan School of Public Health and an expert on step counts and health, that found women in their 70s who managed as few as 4,500 steps a day lowered their risk for premature death from any cause by 40%, compared to those who walked just 2,700 steps or less. The risks for early death continued to drop among the women walking more than 5,000 steps a day, but the benefits plateaued at about 7,500. And a Japanese study last year found that among 4,840 adults aged 40 and up, walking 8,000 steps a day was enough to reduce risk of premature death by 49%.
However, the critical detail is that between 4,000 to 8,000 steps, the benefit was significant, but between 8,000 and 12,000, it tapered off. The statistical benefits of the extra steps were slight, meaning it didn’t hurt people to do more daily steps up to and even beyond the 10,000 mark, but the extra walking didn’t offer much more protection against dying young, either.
Besides, if we do reach the 10,000-step target, we don’t seem to keep it up! In a famous 2005 study in Ghent, Belgium, local citizens were given pedometers and encouraged to walk for at least 10,000 steps a day for a year. Of the 660 men and women who completed the study, about 8% reached the 10,000 step daily goal by the end. But in a follow-up study four years later, almost no one was still striding that much. Most had slipped back to what they were doing at the start of the study.
The good news is that upping our current step counts by even a few thousand strides most days could be a reasonable, sufficient — and achievable — goal, Dr Lee says. Most health authorities recommend 150 minutes of moderate-intensity physical activity a week. Some studies show it’s the number of steps rather than time spent walking that is associated with lower disease risk. Translated to step counts, says Dr Lee, that total would work out to a little more than 16,000 walking steps a week for most people, or about 2,000 to 3,000 steps most days; 2,000 steps is about 1.6km. If we take about 5,000 steps a day going about our everyday activities such as shopping and housework, adding the extra 2,000 to 3,000 steps would take us to a total of between 7,000 and 8,000 steps most days, which, Dr Lee concludes, seems to be the step-count sweet spot.
So, save the time by cutting back on the 10,000-step goal to between 6,000 to 8,000 steps, and use the time saved to do other physical activities such as weight-baring exercise or stretching — which can help prevent muscle and bone-density loss, or loss of flexibility.