Some people get a little fanatical about their exercise. Take I-Min Lee. She walks routinely instead of driving, and she runs regularly. Lee wears a step counter and is “a little obsessed” with keeping track. “This makes me understand how the little things we do during the day can add up to quite a large total number of steps,” the 59-year-old says. Lee admits she has more motivation than the average person. “After all,” she says, “would you listen to a researcher who does not practice what she studies?”
Lee is an epidemiologist at Brigham and Women’s Hospital in Massachusetts who focuses on how physical activity can promote health and prevent chronic disease. Her latest study is actually about steps. Specifically: How many, or how few, an older person needs to take on a daily basis to reap significant health perks.
Along with several other studies out this year, the results reveal the incredible power of simply doing what humans have done since we stopped swinging from trees. And Lee’s results seem to debunk a myth so common it’s programmed into our lives.
For decades, experts have advised us to take 10,000 steps a day for better health. The number is even coded into fitness trackers as a goal. It’s not entirely clear where it came from, though it seems to have originated in the 1960s with Japanese pedometers called manpo-kei, which translates to “10,000 steps meter,” Lee and others say.
Lee wondered if 10,000 was some magic number.
Figuring things like this out is not easy. Most studies on the long-term value of physical activity, if they occur outside a controlled, laboratory setting, rely on self-reporting, which is often inaccurate. Lee and her colleagues solved that by examining data on 16,741 women, ages 62 to 101, who wore accelerometers to measure their movement for a seven-day period during a multi-year study on other aspects of their health.
During four years of follow-up, 504 of the women in the study died. More than half of that group — 275 — had walked only 2,700 steps a day during their test periods. Those who walked more but still a modest amount — 4,400 steps a day — were at 41 percent lower risk of death. The risk of dying prematurely continue to drop up to 7,500 steps a day, then leveled off.
And here’s a kicker: Among people who took the same number of steps during the day, how slow or fast they walked did not matter.
“For many older people, or inactive persons, 10,000 steps/day can be a very daunting goal,” Lee says in an email. She’s got a prescription, based on the study results: “If you are inactive, just adding a very modest number of steps a day — say, an additional 2,000 steps extra — can be very beneficial for your health… you don’t need to get to 10,000.” And, she adds, don’t think of the steps as “exercise.” Any ol’ ambling will do. For example, she suggests, rather than finding the closest parking spot at the grocery store or at a concert, “park at the first spot you can” and hoof it over.
The results were published May 29 in the journal JAMA Internal Medicine.
Oh, and guys? A bit of walking should be just as good for you, too.
“I believe the findings are applicable to men of similar age,” Lee says, “because previous research into physical activity and its benefits for preventing premature mortality and enhancing longevity (which are primarily studies using self-reported physical activity, rather than the device measured steps we used) have shown that there are no differences between men and women.”
She figures the findings would also apply to people in their fifties.
Novel and meaningful as Lee’s study is, it does not prove cause-and-effect. Steps may improve health, or healthier people may take more steps. But Lee and her colleagues say the findings are “more likely causal than not,” given that they excluded from the study women with heart disease, cancer, diabetes, plus anyone who rated their health as less than good.
“This study is a great contribution” to the literature showing the value of moderate physical activity, says Tom Yates, who studies the health aspects of physical activity at the University of Leicester.
“I think over the next couple of years we will see a change in the ‘more is better’ mentality that has currently dominated, at least in terms of all-cause mortality,” says Yates, who was not involved in Lee’s work. “At the opposite end of the spectrum, there is also mounting evidence that exercising to excess can be damaging for the heart and course long term damage.”
In May, Yates and his colleagues learned something about walking that is a little different than the results of Lee’s study. People who described themselves as brisk walkers (versus steady or slow) live notably longer, the researchers reported in the journal Mayo Clinic Proceedings. The study involved 474,919 people with data across seven years. And while the data relied on self-reporting of activity, the results were surprising in one respect: They held regardless of body mass index (BMI), body fat percentage or waist size.
“Fast walkers have a long life expectancy across all categories of obesity status, regardless of how obesity status is measured,” Yates says.
Read the full article here: https://elemental.medium.com/the-case-for-walking-431b82f1eaa9
