The Case for Walking
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…