In the era of Fitbits, Apple Watches, Oura rings, and smartphones that can track our every move, you’ve almost certainly heard that 10,000 steps a day is the target. “There were no actual studies that had looked at ‘10,000 steps,’” at the time the Yamasa pedometer was developed, I-Min Lee, an epidemiologist at Harvard Medical School, tells Popular Science. They found that far less than 10,000 steps could make a big difference for longevity. Women who averaged around 4,400 steps had significantly lower mortality rates over four years of follow-up than those who averaged about 2,700 steps. Going from 2,000 steps a day to just 4,000 or so is associated with about a 30 percent decrease in all-cause mortality, Clare says.