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Entire television series, such as the twenty-sixth season of the American hit series The Amazing Race, have been organized around the idea of using devices like a pedometer, or a FitBit, to keep track of physical activity. Fit people get lots of exercise, the experts tell us, and activity trackers prove it, or at least they should. When the ideas that most Americans are physically active as if they walked 10,000 steps a day and most fit people are that physical active were put to the test, however, researchers got shocking results.
Where Did Experts Get the Idea That We Should All Get More Exercise?
For nearly 60 years, doctors have been telling us that physical activity is essential to good health. In 1953, the Scottish epidemiologist Jeremiah Morris observed that ticket collectors on double decker buses were 50 percent less likely than drivers of the same buses to have heart attacks. The difference in the two jobs was that the ticket collector had to climb on average about 600 steps per day. To Dr. Morris, exercise had to make the difference. In the 1960’s, when the United States anticipated another war, with the Soviet Union, the US government was eager to make sure youth stayed in shape. In 1966, President Lyndon Johnson created national physical fitness awards, and in 1968 Dr. Kenneth Cooper, formerly a fitness expert for the US Air Force, invented the term “aerobics.” International standards took a while to catch up. In 1996, the World Health Organization announced that, worldwide, 6 percent of all deaths were associated with lack of exercise.
What doctors, patients, and the people who write articles about health failed to realize was that the World Health Organization was really saying that if everyone got exercise, it was highly probable that there would be 6 percent fewer deaths per year. This wasn’t the same as saying your risk of death will be 6 percent higher if you don’t exercise.
How Did Experts Come Up with the Figure of 10,000 Steps Per Day?
Researchers have also gone about computing how much exercise, on average across the entire population, is necessary to eliminate lack of exercise as a public health concern. In the United States, the Centers for Disease Control decreed that:
- Children should get an hour of physical activity every day.
- Adults should get 5 hours of moderate exercise per week, something like brisk walking, for maximum benefits, or at least 2-1/2 hours of moderate exercise per week for measurable health benefits. “Intense” exercise cuts the time requirement in half.
- A study of adults in the obesity-prone states of Louisiana and Mississippi in the United States found that 9,154 steps a day would equal one half-hour of moderate to vigorous physical activity. From this the experts concluded that sedentary people walk 7,500 steps per day or less and active people walk more than 10,000 steps per day. It didn’t hurt that at the time the recommendation was made, the most readily available pedometer was made in Japan, and it was calibrated to tell people precisely when they had walked 10,000 steps in a single day.
All of these figures, of course, are entirely arbitrary. That doesn’t mean it’s not a good idea to walk 10,000 steps per day. It just means that the recommendation to walk 10,000 steps a day is a best guess. Or at least it was. Modern technology makes measurement a lot easier, and a recent study puts the 10,000 step a day figure in doubt.