Today I Learned: The 10k Steps Goal Is Actually an Ad

It's an easy number to remember: 10,000 steps per day. Reach it, and your smartwatch goes on celebratory mode: digital fireworks, a rocket ship in the background, the words "Goal Reached!" in capital letters, and an image of a trophy or a medal. That victory buzz—almost a haptic high-five—on your wrist just feels different after covering about eight kilometers of walking or running, whether in one go or in small increments throughout the day. Complete 10,000 steps, and it's as if you've added another day to your dream of a long and healthy life. An 8,500 or even a 9,999 step count doesn't even feel enough.

But, as much as we love closing the loop of the four zeroes, the specific number of 10,000 steps per day actually has “limited scientific basis,” according to Dr. I-Min Lee. An associate epidemiologist at Brigham and Women’s Hospital and a professor of medicine at Harvard Medical School, she and her colleagues published a 2019 study titled "Association of Step Volume and Intensity With All-Cause Mortality in Older Women" in JAMA Internal Medicine. That’s not to say, of course, that walking thousands of steps has no health benefits.

Before rulers, tape measures, and pedometers, measurement methods were based on the human body. An inch is equal to the width of the thumb, a foot is equal to the length of the foot (obviously), and so on. Step counting, likewise, had long been used to measure distance as the word "mile" actually comes from the Latin phrase milia passuum, meaning "one thousand paces." One mile was approximately 1000 paces (or 2000 steps).

Leonardo da Vinci is credited with inventing (or, at least, conceptualizing) the first mechanical step counter in the 15th century. His sketched plans show a gear-driven device with a pendulum arm that swings back and forth for every leg motion. The device is believed to track the distance that a Roman soldier walked and, likely, to also aid in creating more accurate maps. (Again, steps = distance.)

In 1525, French craftsman Jean Fernel created a device that looked like a pocket watch. It had four dials, a mechanism attached to the user's belt, and a cord attached to the user's right knee. Every time that knee would pull on the device (a.k.a. take a step), the dials would turn.

Thomas Jefferson, in the 18th century, traveled to France and brought back a mechanical pedometer to the U.S. The commissioned piece required the user to hang it from the watch pocket, pass a tape attached to the bottom of the device through a hole in the bottom of the bocket, and attach the hook to the knee. Jefferson measured the distance between Paris landmarks in steps and noted that an English mile would require 2066.5 steps. He sent the device to James Madison in 1788 along with a detailed one-page letter of instructions.

While step counters of the past had the sole purpose of measuring distance, the modern-day devices have a fitness-related goal, much like our Garmin and Fitbit. And that includes the origin story of the 10,000 steps per day goal.

In the mid-1960s, there was growing concern among doctors and clinicians in the Land of the Rising Sun that Japanese society was becoming dependent on the conveniences of modern living: from escalators to lifts, cars, and other so-called symbols of modernity and development.

One of them was Iwao Ohya, head of one of Tokyo's biggest clinics, who observed the low levels of physical activity among the Japanese to engineer Juri Kato of clockmaker Yamasa Tokei Keiki. That was in 1963, while the country was busy preparing for the 1964 Olympics—ironically, the interest in sports was relegated to spectacle.

By 1965, Yamasa (a.k.a. Yamax) made and marketed a pedometer called Manpo-kei, which literally translates to "ten-thousand step-meter." (Yes, as in 10,000 steps.) Plus, the Japanese symbol for 10,000 looks a bit like a walking person (if you squint really hard).

The number stuck. The pedometer was sold. Walking clubs emerged, including the Japan Walking Association.

It wasn't until the late 1970s that science was brought in to justify the 10,000-step marketing scheme. A researcher at Tokyo Gakugei University, Dr. Yoshiro Hatano, built on the landmark study of Dr. Ralph Paffenbarger, a Stanford University researcher who reported in 1977 that there were fewer heart attacks among those who engaged regularly in sports and other physical activities, specifically those who burned 2,000 calories a week. This was based on a survey conducted among men aged 35 to 75 (of 17,000 Harvard alumni).

From these numbers, Hataro tried to find out exactly how many steps a day could burn almost 300 calories (from 2,000 calories a week divided by seven days). With the use of pedometers and treadmills, as well as the help of walking groups, he came up with 10,000 steps.

It was also around this time that Yamasa began registering trademarks for "Manpo Meter," "Manpokei," and "Manpo," effectively making the 10,000-step goal an international standard. Step-count and pedometer research eventually became a proper field of study, with journal articles increasing per year. Most fitness watches even make 10,000 steps per day the default target.

At present, however, there is a growing argument that step goals are not one-size-fits-all. Other studies say it's 7,500 steps for women in their 70s, another says it's 8,000 to 10,000 a day for people younger than 60, then another suggests 7,500 for adults. And then there's a whole other argument on whether the exact number of steps even matters, and if it even connects to the intensity of the activity.

All we know at this point is that the best physical activity is the one that's best for you, which means to say something you could do regularly.

References:

Bassett, D. R., Toth, L. P., LaMunion, S. R., & Crouter, S. E. (2016). Step counting: A review of measurement considerations and health-related applications. Sports Medicine, 47(7), 1303–1315. https://doi.org/10.1007/s40279-016-0663-1

Brody, J. (1977, November 29). Study of 17,000 men indicates vigorous sports protect heart (published 1977). New York Times. https://www.nytimes.com/1977/11/29/archives/study-of-17000-men-indicates-vigorous-sports-protect-heart-study-of.html

Calechman, S. (2019, July 11). 10,000 steps a day - or fewer?. Harvard Health. https://www.health.harvard.edu/blog/10000-steps-a-day-or-fewer-2019071117305

Lee, I.-M., Shiroma, E. J., Kamada, M., Bassett, D. R., Matthews, C. E., & Buring, J. E. (2019). Association of STEP volume and intensity with all-cause mortality in older women. JAMA Internal Medicine, 179(8), 1105. https://doi.org/10.1001/jamainternmed.2019.0899