Sitting Isn’t Killing You, But Your Chair Might Be
Sitting is the new smoking, but how you sit has more impact than how much you sit
The new smoking
Have you reached your 10,000 steps for the day? It’s a goal many people set themselves (even though it probably originated in a 1960s marketing campaign).
Regardless of the origin of the 10k step directive, or the exact numbers of steps we need, it is clear that the general decline in physical activity is doing us no favors.
Add to this that, in the majority of modern workplaces, we tend to sit in (somewhat) cozy desk chairs for most of the daylight hours. Result: humanity has probably never sat more on its behind than it does today.
Sitting in a shapely chair might be comfortable, but it’s not exactly healthy. Sedentary time is correlated with increased all-cause and cardiovascular disease mortality risk and detrimental changes in cardio-metabolic and inflammatory biomarkers. In fact, unless you reduce your caloric intake, sitting down for one day already affects insulin action.
This feels intuitive. After all, once upon a time, our ancestors roamed the savannah, walking long distances and chasing prey for hours or even days. Our feet were made for walking, our behinds not for sitting.
The devil’s in the chair
While we can’t study our ancestors, anthropologists often use modern hunter-gatherer societies as a proxy for our evolutionary past.
The Hadza people in Tanzania, a current hunter-gather culture, have participated in many anthropological investigations due to their lifestyle, which is thought to reflect that of our distant ancestors.
The Hadza, on average, have no problem tallying the 150 minutes of moderate-to-vigorous activity per week that is recommended for cardiovascular health. Many people in industrialized societies, again on average, do not hit that number.
However, does this mean that the Hadza don’t sit? 150 minutes per week still leaves a lot of time to be filled.
A new study tracked the movement patterns of Hadza participants (16 men and 12 women, ranging between 18 and 61 years of age) with activPal accelerometers — with informed consent, of course. Surprisingly, the researchers find that, despite their 150 minutes of moderate-to-vigorous activity, the Hadza spend about the same time ‘nonambulatory’ (aka not moving around) as do people in western, industrialized societies (in this case, data from the Netherlands, Australia, and the US).
What’s going here?
Turns out that it’s not so much the time spent sitting, but how you sit.
The detrimental effects of sitting too much are thought to come from muscle inactivation, which in turn affects metabolism, which, one step further down the metabolic pathway, has knock-on effects on inflammation, insulin, and so on.
But, what if you could sit while encouraging at least some muscle activity?
That’s exactly what the Hadza do. ‘Chair-style sitting’ accounted only for a very minor proportion of their seated time. Instead, they preferred ground-sitting postures, squatting, and kneeling.
Further electromyography (EMG) data revealed that, as hypothesized, the sitting postures preferred by the Hadza elicited significantly more muscle activity. In other words, their resting is much more active than the resting in industrialized societies.
It would be arrogant to think we have nothing left to learn from non-western, non-industrialized cultures:
Replacing chair sitting and associated muscular inactivity with more sustained active rest postures may represent a behavioral paradigm that should be explored in future experimental work. While squatting is not a likely alternative, spending more time in postures that elicit low-level muscle activity could lead to more beneficial health outcomes.
So, don’t be afraid to sit down, but maybe try sitting on the floor, squatting, or a Swiss ball next time.