If you are sitting down to read this article, you may be doing your resting wrong, according to a fascinating new study of hunter-gatherer tribespeople and how they idle. The study finds that hunter-gatherers tend to lounge about during the day almost as much as those of us in the developed world. But their approach to inactivity is distinctive, involving no chairs and plenty of squatting.
This difference could have implications for our metabolic and heart health and also raises questions about how and why our style of sitting seems to be so unhealthy.
It is something of a paradox that inactivity is associated with ill health in so much of the world. Rest, after all, seems as if it should be good for us. But study after study links more time spent sitting with increased risks for poor cholesterol profiles, heart disease, diabetes and other conditions, even among people who exercise.
This enigma — that sitting seems to contribute to sickness — began to interest a group of scientists who long have worked with and studied modern hunter-gatherers, hoping to better understand the evolutionary context of physical activity in human development.
In some of their past research, these scientists had shown that members of the Hadza tribe in Tanzania are quite physically active, devoting several hours a day to activities like following game or tugging up tubers. They also have enviable cardiovascular and metabolic health, with low blood pressures and healthy cholesterol profiles throughout their lives.
But several hours of physical activity a day leave multiple waking hours open, and the researchers began to wonder recently whether the ways in which the Hadza spend their downtime might be contributing somehow to their well-being.
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.