Can you Live Longer by Sitting Less?
A Lesson for Stay@Home during the Pandemic
Is sitting your most common activity? Do you sit for 8 hours or more daily? Even people who exercise for an hour or so tend to spend most of the remaining hours of the day in a chair.
The health consequences of this sedentariness are well-documented. Past studies have found that the more hours that people spend sitting, the more likely they are to develop diabetes, heart disease and other conditions, and potentially to die prematurely — even if they exercise regularly.
Most of the studies are not conclusive as to whether or how sitting actually causes ill health.
A groundbreaking study some time ago by some Swedish scientists published in the British Journal of Sports Medicine wanted to know how changes in sedentary time would affect “telomeres” in people. They tracked certain physiological results from the variable amount of time that people spent exercising and sitting.
Telomeres are the tiny caps on the ends of DNA strands. They shorten and fray as a cell ages, although the process is not strictly chronological. Obesity, illness and other conditions can accelerate the shortening, causing cells to age prematurely, while some evidence suggests that healthy lifestyles may preserve telomere length, delaying cell aging.
In the Swedish experiment, a group of normally sedentary and overweight men and women above 68 years old volunteered their blood in order to measure the length of telomeres in the white blood cells. Thereafter, half the group, randomly selected, were put through a moderate individual exercise program, and advised to sit less. The other half remains as the control group, living their life normally.
After 6 months, a 2nd blood sample was drawn together with records regarding their daily activities. The results comparing the telomeres of both groups showed that those in the first group who began to exercise more than previously and sitting much less had longer telomeres, and their cells seemed to be growing physiologically younger.
By contrast, the telomeres in the control group were generally shorter than 6 months previously.
The most interesting finding was however that there was little correlation between exercise and telomere length. In fact, the first exercise group who had been working out during most of the past six months tended thereafter to have slightly less lengthening and even some shortening, compared to those who had exercised less but stood up more.
The scientists concluded that reducing sedentary time had lengthen the telomeres, while exercising had played little role in that effect.
Standing is not, after all, physically demanding for most people, and some scientists have questioned whether merely standing up — without also moving about and walking — is sufficiently healthy or if standing merely replaces one type of sedentariness with another. If so, standing could be expected to increase health problems and premature death, as sitting has been shown to do.
In another study published in the Medicine & Science in Sports & Exercise, a Dr. Peter Katzmarzyk found no link between standing and premature death. Rather, he observed that “mortality rates declined at higher levels of standing,” suggesting that standing is not sedentary or hazardous, a conclusion with which our earlier telomeres study would likely concur. He based the study on a large database of self-reported information about physical activity among Canadian adults. He then studied the amount of time that they had reported standing on most days over the course of a decade or more and crosschecked that data with death records, to see whether people who stood more died younger. They did not.
The key takeaways are that some exercise is better than no exercise just to stay healthy and fit, and that these exercises can be done standing or sitting or lying down or whatever. And if you were just standing or sitting, why not try to do something at the same time such as stretching or swinging your hands as well as some squatting and feet raise.
