Health sciences - deadly chairs / James Levin

Studies show that if we stand for longer periods of time, even in an office job, we will reduce the risk of obesity, disease and death

Chairs: we sit on them, and use them at work, shopping, dining and spending time as a couple. Americans sit for most of their waking hours, an average of 13 hours a day. But the chairs are killer.

This bleak conclusion may surprise you, but it is supported by 18 studies conducted in the last 16 years that surveyed a total of about 800,000 people. For example, in 2010 the scientific journal Circulation published a study that followed 8,800 adults for seven years. The death rate in people who sat for more than four hours a day watching television was 46% higher than in people who sat in front of the screen for only two hours. Other studies have suggested that sitting for more than half a day, roughly, doubles the risk of diabetes and coronary problems. The conclusion is, therefore, that when you sum up all the mortality factors and compare people who sit a lot with people who are more active, those who sit have a 50% higher risk of dying.

Sitting for a long time is bad because the human body was not designed to be inactive. I have been researching obesity for 40 years and my laboratory has examined the effect, at the molecular level, of a sedentary lifestyle, to the point of examining the effect of office design. The lack of activity slows down the rate of metabolism, reduces the amount of food that is converted into energy and therefore promotes fat accumulation, obesity and a variety of diseases that accompany being overweight such as heart disease, diabetes, rheumatism and more. Sitting is also harmful to thin people. For example, sitting in a chair after a meal leads to a sharp rise in blood sugar, while moving after eating cuts the rise in half.

The public often associates these health problems with eating too much, rather than sitting for too long. My experience with people struggling with their weight has led me to believe that sitting habits are just as harmful. Also, it may be easier to change a sedentary lifestyle than eating habits.

Peter (pseudonym), who attends one of my programs in Minneapolis, told me "I'm stuck". He was 44 years old, 25 kilos overweight and type 2 diabetes. His doctor wanted him to start injecting insulin. I referred him to my lab at the Mayo Clinic. There he watched the data of his metabolic rate measurements: walking slowly at a pace of less than three kilometers per hour increased his energy production by 200 calories per hour. Afterwards, Peter and I walked and talked. "If you conduct two of your daily meetings this way," I explained to him, "you'll burn an extra 400 calories a day."

Peter listened to my advice. He didn't diet, but in the first year after the measurements, he lost 11 kilos. He reduced another 4.5 the following year. Peter did not need insulin, like many diabetics who reduce their weight, and stopped taking diabetes medication altogether. He also implemented the "stimulating" message at home: he started going on bike rides and trips to art galleries with his family.

Peter is not a single success case. Many studies support the idea that simple activity has dramatic effects on health. What's more, the effect doesn't involve three visits a week to the gym or daily runs that people drop as soon as the schedule becomes less convenient. Sometimes an activity that is not exercise is enough, if it is performed several times a day. Employees, companies and schools have already begun to establish a set of procedures that will encourage employees to get up from their chairs.

Miracle underwear

Much of the evidence for the benefits of simply standing and walking during the day came from studies that my research group conducted since 2001, which compared people in agricultural communities with people living in an industrialized and urban environment, like Peter. To test sitting and movement, we took lycra underwear and added tiny motion and posture sensors to them that monitor body movements in 13 directions every half a second. My colleagues and I jokingly called them "wonder panties", but they collected a large amount of information. We asked villagers from an area of ​​banana plantations in Jamaica, urbanites in Kingston, the capital of the island, and urbanites in the US to wear the underwear for 10 days. Among our findings: the people who live in rural areas in Jamaica walk twice as thin as even the thin people in Kingston and modern cities in the USA. Residents of the agricultural communities sit for only three hours a day, while office workers can sit for 15 hours a day. Because of the increased activity, as we wrote in the summary of the research published in 2011 in the journal Urban Studies, agricultural work "burns" 2,000 calories a day more than many office jobs do.

The possibility that exchanging sitting time for walking could use up so many calories piqued my curiosity. I called the phenomenon "heat generation through non-exercise activity" (and NEAT in its initials). NEAT is the amount of energy a person expends during daily life. I wondered if it affects the weight of people who do similar work and live in similar environments, and not just our agricultural and urban workers.

To get an idea, we compared thin and fat people in the US, all of whom live in a similar environment and have similar jobs and eating habits. We asked the subjects to put on the miracle underwear, and they discovered that fat people sit 2.25 hours more every day than their thin counterparts. The sedentary obese people expended 350 fewer calories each day during walking and other NEAT activities than lean people.

The pattern of behavior seems convincing, but not certain. To see if such levels of non-exercise activity could cause weight gain, we started what we called the "Great Binge Experiment." We asked 16 lean volunteers to binge eat under our strict monitoring. Every day for eight weeks, each volunteer was fed food with an energy value of 1,000 calories more than their normal energy needs.

Some of our volunteers were like the annoying friends we all have, the ones who don't get fat despite the constant consumption of donuts. Such volunteers added almost no body fat after eight weeks and a total of 56,000 extra calories. How did they stay thin? Our underwear sensors showed that they had increased their NEAT levels, although none of them were aware of it. On the other hand, other volunteers who binged, didn't change their NEAT and remained glued to their chairs, invested almost every extra calorie in creating body fat, as we reported in a 1999 Science article.

These people ignored the tendency to move, which is a biological tendency like breathing. In animals, movement allows predators to chase, threatened ones to escape, live gatherings to search, and those in breeding season to find mates. Experiments in rodents show that there are complex brain circuits that monitor and respond to calorie burning, activity and rest. They are located in an area called the hypothalamus, which also regulates actions such as body temperature and sleep-wake cycles.

Moreover, researchers have established during the last decade that part of the hypothalamus regulates appetite and makes us hungry if we spend the whole day in activities like raking leaves. At the same time, a muscle feedback system senses the overactivity of the muscles and signals us to sit down and rest. The modern sedentary environment has silenced this biological balancing act.

what can we do?

We are not prisoners of our environment. we can break free Although technologies such as computers and video games increase the appeal of the chair, technology can also be part of the solution. The cell phone, for example, allows a conversation while sitting to become a conversation while walking. A variety of popular activity monitoring gadgets allow people to measure how often they sit, stand, and move. Newer video games, called exergames, match computers with sports competitions: the Nintendo Wii is the one that first changed the rules of the game.

Work can also be more active. My lab has redesigned workplaces that free the workers from the isolation that the chair imposes on them. One company in St. Paul, Minneapolis encourages walking meetings by taping walking tracks to the carpets. A company in Iowa is trying to prevent employees from sending e-mails to their nearby colleagues by creating "e-mail-free work zones"; Computer networks can block emails to nearby desktops.

Ten years ago, I came up with the idea of ​​a desk that is also a treadmill as a way to allow office workers to work on the move. The unit allows people to walk while they go about their business. The computer is placed on a high table with a treadmill set to a low speed (1.5-3 km/h). Employees can go to ATM while typing, answering emails and talking on the phone. By nature, as an inventor, I believe that this desk is a good idea, and I was happy when a study, published in the journal Health Services Management Research In 2011, he showed he could be effective. The article reported that people who used the desk were thinner, less stressed and had lower blood pressure and cholesterol levels. The table, of course, is not the only way to incorporate activity during the day. Like offices, schools can also be more active places. We helped build a classroom in Rochester, Minneapolis, where students practiced spelling while walking and math while throwing balls. In Idaho Falls, in a redesigned classroom, all the sitting desks were replaced with standing desks that included a sort of "motion shelf" that the students could use to wiggle their legs. Studies have shown that students attending schools that encourage movement are twice as active as students in regular schools. Their grades also improved by about 10% and their hormone levels were in healthier ranges.

It is also possible to imagine entire cities that would encourage movement. Analysis of data from San Francisco and the UK showed that urban districts could be rezoned to discourage people from driving. The arrival time is extended by only a few minutes, the air quality improves and the medical expenses decrease. A chair-free life not only improves health but also saves money.

We live in a sea of ​​killer chairs: adjustable, swivel, easy chairs, armchairs, sofas, four-legged, three-legged, made of wood, leather or plastic, in the car, on the plane, on the train, in the restaurant and in the bar. This is bad news. The good news is that you don't have to use them. Pat yourself on the back if you read this article standing up - if not, then stand up now!

About the author

James Levine is a physician and endocrinologist who directs the Obesity Solutions Initiative, a joint program of the Mayo Clinic in Rochester, Minneapolis, and the University of Arizona. He is the author of the book "Get up!" (Palgrave Macmillan, 2014). Levin also invented a work desk that doubles as a treadmill, but receives no money from sales of these desks.

The article is published with the approval of Scientific American Israel