According to the fossil record, human beings began walking long distances about 1.89 million years ago, towards the end of the Pliocene epoch. It was only more recently, during the age of the Fitbit, that all able-bodied men and women were expected to take 10,000 steps a day. Now two studies, which together involved more than 20,000 Americans, have cast doubt on this target.
One study, involving more than 17,000 women between the ages of 62 and 101, showed the benefits of walking began to taper off after about 7,500 steps. Another study, involving a younger cohort of about 4,000 Americans, aged 40 and upwards, suggested there were health benefits from more steps but also showed those benefits dwindling before the 10,000-step mark.