There are many reasons I love walking. For one, it’s easy. Almost everyone can lace up a pair of shoes and walk outside (or inside). Heck, all the movement we do in a day, including chores, running errands, and walking to the office (if that’s still a thing), add up to the total number of steps we complete each day.
Walking can also improve your mood, help you destress, provide heart-pumping exercise, and even help the waistline. The American Heart Association recommends getting at least 150 minutes per week of moderate-intensity aerobic activity or 75 minutes per week of vigorous aerobic activity, or a combination of both preferably spread throughout the week.
They also advise spending less time sitting. Even light-intensity activity can offset some of the risks of being sedentary. Prolonged sitting (defined as sitting for more than 2 hours) is linked to an increased risk of obesity and type 2 diabetes.
While fitness trackers and smartwatches almost always set a daily target of 10,000 steps, there’s limited scientific evidence about whether 10,000 is some “magic” number. In fact, 10,000 steps began as a marketing campaign by a Japanese pedometer company.
Authors of a March 2020 study published in the Journal of the American Heart Association acknowledged that higher step counts are associated with lower mortality. Still, previous studies were conducted in older adults, in individuals with debilitating chronic conditions, or in cohorts with relatively few deaths, which may limit generalizing that theory to the majority of the population.
For this reason, they set out to examine the association between step count, intensity, and risk of death in a broader range of the U.S. population. They used data on physical activity collected by a national health survey, the National Health and Nutrition Examination Survey (NHANES), between 2003–2006.
The research team studied participants 40 and older who wore an accelerometer during their walks for one week. An accelerometer measures not just steps but how fast you take them (steps per minute). Then they followed those subjects for the next decade, specifically tracking how many died and the cause of death.
According to the National Institutes of Health,
During the decade of follow-up, 1,165 out of the 4,840 participants died from any cause. Of these, 406 died from heart disease and 283 died of cancer.
Compared with people who took 4,000 steps a day, those who took 8,000 steps a day at the start of the study had a 50% lower risk of dying from any cause during follow-up. People who took 12,000 steps a day had a 65% lower risk of dying than those who took only 4,000.
Higher step counts were also associated with lower rates of death from heart disease and cancer. These benefits were consistent across age, sex, and race groups.
It’s important to add no one has proven cause and effect — only that walking more seems to go hand in hand with living longer. It could be that people who walk more steps eat better, exercise more, and avoid things like smoking and excess alcohol use.
First author Dr. Pedro Saint-Maurice of NCI explained,
We wanted to investigate this question to provide new insights that could help people better understand the health implications of the step counts they get from fitness trackers and phone apps.
What’s interesting is step intensity did not seem to impact the risk of mortality once the total number of steps per day was considered. As far as this study is concerned, it’s more important to focus on total steps vs. how fast you take those steps.
It’s surprising (to me) that the intensity of walking had no clinically significant impact in this study, but it aligns with other research findings. It’s important to remember total steps include more than a dedicated walk. This number is also a reflection of how much you move around during the day.
As with anything in science, nothing is absolute. You can find conflicting studies on just about any topic.
Scientific American reports,
A new analysis of walking speed studies shows that — down to the tenth of a meter per second — an older person’s pace, along with their age and gender, can predict their life expectancy just as well as the complex battery of other health indicators.
Of the 34,485 adults in the studies, people with average life expectancy walked at about 0.8 meter per second. For those with a gait speed of one meter per second or faster “survival was longer than expected by age and sex alone,” the researchers noted in their article.
How fast you walk likely has a lot to do with your leg strength and overall fitness level. Speed also tends to decline with age.
Regardless, the scientific message is clear. Walking around 8,000 to 12,000 steps per day has the potential to prolong your life. So lace up those shoes and head outside!