So, for the new study, which was published Monday in Proceedings of the National Academy of Sciences, the researchers first asked 28 Hadza tribesmen and tribeswomen, ranging in age from 18 to 61, to wear activity trackers for about a week. The trackers, worn on the tribespeople’s thighs, would measure how much time they spent moving and still.
And it turned out they often were still. As in the earlier research, the new measurements showed that, on average, the men and women were in motion daily for about two or three hours, but also inactive for another 10 hours.
That amount of inactivity “almost perfectly matches” the levels seen in studies of men and women in the developed world, says David Raichlen, a professor of human evolution at the University of Southern California in Los Angeles, and lead co-author of the new study.