Resting postures such as squatting or kneeling may be better for health because require more muscle activity than sitting on a chair, researchers claim.
The findings are based on data gathered from a hunter-gatherer population in Tanzania who wore devices that measured physical activity as well as periods of rest.
Anthropologists from the US found that despite being sedentary for almost 10 hours each day, equivalent to clocking a shift in the office at the desk, the Hazda people appeared to lack the markers of chronic diseases associated with long periods of sitting.
They believe this is down to the ‘active rest postures’ used by the tribe.
Dr David Raichlen, a professor of biological sciences at the University of Southern California’s Dornsife College of Letters, Arts and Sciences, and lead author on the study, said: ‘Even though there were long periods of inactivity, one of the key differences we noticed is that the Hadza are often resting in postures that require their muscles to maintain light levels of activity – either in a squat or kneeling.’
Prolonged sitting has been linked to an increased risk of cardiovascular disease and death, but according to the researchers, this contradicts the evolutionary aspect which favours strategies that conserve energy.
Brian Wood, an anthropologist at the University of California, and one of the study authors, said: ‘Preferences or behaviours that conserve energy have been key to our species’ evolutionary success.
‘But when environments change rapidly, these same preferences can lead to less optimal outcomes. Prolonged sitting is one example.’
To find out more, the researchers looked at the data from 28 Hadza adults who wore devices, known as accelerometers, for eight days and compared it with the information gathered from previous studies that measured inactivity in modern working populations.
They found that their test subjects had high levels of physical activity for just over an hour a day alongside several hours of inactivity, between nine to 10 hours a day. But despite remaining in resting postures for long periods of time, the Hazda people did not show any signs of the health conditions associated with a sedentary lifestyle.
The researchers said is because the Hazda squatting and kneeling uses more muscle movement than sitting on a chair.
They believe these active rest postures may help ‘protect people from the harmful effects of inactivity’.
Dr Raichlen said: ‘Being a couch potato – or even sitting in an office chair – requires less muscle activity than squatting or kneeling.
‘Since light levels of muscle activity require fuel, which generally means burning fats, then squatting and kneeling postures may not be as harmful as sitting in chairs.’
The study is published in the journal Proceedings of the National Academy of Sciences (Pnas).
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