Why chairs are bad for you

This conversation begins at birth, and continues as babies first lift their head, then creep, then crawl, then toddle and finally stand. Throughout this awakening of the body the spine is adapting to gravity, developing the normal curves in the lower back, thorax and neck that allow for perfectly balanced, calorically efficient standing and sitting while at rest.

Simultaneously the body is also developing muscular reflexes that facilitate efficient posture, reflexes that adjust the spine moment to moment to assure balanced, stable posture. Importantly, these reflexes also allow the spine to adjust on the fly to surprises that might cause a fall if not compensated for. The back rest, arm rests, foot rests, head rests all require that the spine respond with new, unusual, conformations.

Unfortunately, these new, unusual, conformations can cause discomfort in the short run: witness the frequent changes of sitting positions required when sitting for more than a few minutes. Because our brains are embodied in our bodies, posture also affects the mind. This is in part the basis of yoga and meditation: certain postures help the mind to find its groove. Because active sitting profoundly affects posture, it is likely that it also improves mental states.

But spinal reflexes are very real and very important. For example, if you put your hand on a hot stove you will immediately and involuntarily jerk it away, before you actually feel the heat or pain. At the spinal cord this information is sent on to two places: 1. This direct connection of the pain sensors in your hand to the flexor muscles in your arm at the spinal level is called a spinal reflex. The result is mysterious, almost magical: you move your arm before you feel the burning of your hand.

The pattern was suggestive but not definitive. Every day for eight weeks, each volunteer received 1, calories a day beyond their normal energy needs. Some of our volunteers were like those frustrating friends—we all seem to have them—who do not put on weight despite continuous doughnut consumption.

These volunteers gained almost no body fat after eight weeks and a total of 56, extra calories. How did they stay thin? Our underwear sensors showed they increased their NEAT levels, although none of them said they made a conscious effort to do so.

In contrast, other overfed volunteers deposited almost every extra calorie in their body fat. The reason that these volunteers gained so much fat was that they did not change their NEAT—they remained stuck to their chairs, as we reported in Science in These people were ignoring a drive to move that is as biological as breathing.

In animals, movement enables aggressors to chase, the threatened to flee, the forager to search, and the reproductive to find mates. Rodent experiments show that there is intricate brain circuitry that monitors and responds to calorie expenditure, activity and rest. It is located in an area called the hypothalamus, which also regulates such functions as temperature and sleep-wake cycles. Moreover, investigators have determined over the past decade that part of the hypothalamus manages appetite and will make you hungry if you spend a whole day raking leaves.

Meanwhile a feedback system from the muscles senses muscular overexertion and signals a person to sit and rest. The modern chair-based environment has overwhelmed this biologically driven balancing act. What Can We Do? We are not, however, prisoners of this environment. We can break free. Although technologies such as computers and video games have contributed to the allure of the chair, technology can also be a part of the solution.

The cell phone, for instance, enables a seated conversation to become a walking talk. A host of popular activity-sensing gadgets enable people to measure how often they sit or stand or move. Newer video games, called Exergames, link computers to physical competitions; the Nintendo Wii, which encourages movement, was a game changer here.

Work can become more active as well. On behalf of some corporations, my lab has redesigned workplaces that release employees from their chair-based isolation. One company in St. Paul, Minn. A decade ago I came up with the idea of a treadmill desk as a way to allow office workers to do their jobs while moving. The unit allows people to walk while conducting business. A computer is placed on a high table with a slow-speed 1 to 2 mph treadmill underneath it. A person can stroll while typing, answering e-mails and taking phone calls.

Naturally, as the inventor, I think the desk is a good idea, and I was pleased when a study, published in Health Services Management Research in , demonstrated that it could be helpful.

It reported that people who use the desks are slimmer, are less stressed, and have lower blood pressure and cholesterol levels. The desk, of course, is not the only way to incorporate more activity into your day. As is true of offices, schools can become more active places. These large muscles are important for walking and for stabilising you. If these muscles are weak you are more likely to injure yourself from falls, and from strains when you do exercise.

Moving your muscles helps your body digest the fats and sugars you eat. If you spend a lot of time sitting, digestion is not as efficient, so you retain those fats and sugars as fat in your body.

Even if you exercise but spend a large amount of time sitting, you are still risking health problems, such as metabolic syndrome. The latest research suggests you need 60—75 minutes per day of moderate-intensity activity to combat the dangers of excessive sitting.

Just like your legs and gluteals, your hips and back will not support you as well if you sit for long periods. Sitting causes your hip flexor muscles to shorten, which can lead to problems with your hip joints. Poor posture may also cause poor spine health such as compression in the discs in your spine, leading to premature degeneration, which can be very painful. This might be because people who spend a lot of time sitting are missing the positive effects of physical activity and fitness.

If so, getting up and moving may help. Emerging studies suggest the dangers of sitting include increasing your chances of developing some types of cancer, including lung , uterine , and colon cancers.

The reason behind this is not yet known. Sitting for long periods has been linked to heart disease. One study found that men who watch more than 23 hours of television a week have a 64 per cent higher risk of dying from cardiovascular disease than men who only watch 11 hours of television a week.

Some experts say that people who are inactive and sit for long periods have a per cent higher risk of suffering a heart attack or stroke. Studies have shown that even five days lying in bed can lead to increased insulin resistance in your body this will cause your blood sugars to increase above what is healthy.

Research suggests that people who spend more time sitting have a per cent higher risk of diabetes. Sitting for long periods can lead to varicose veins or spider veins a smaller version of varicose veins.

This is because sitting causes blood to pool in your legs. In rare cases, they can lead to blood clots, which can cause serious problems see deep vein thrombosis, below.

Sitting for too long can cause deep vein thrombosis DVT , for example on a long plane or car trip. A deep vein thrombosis is a blood clot that forms in the veins of your leg. DVT is a serious problem, because if part of a blood clot in the leg vein breaks off and travels, it can cut off the blood flow to other parts of the body, including your lungs, which can cause a pulmonary embolism.

This is a medical emergency that can lead to major complications or even death. If you spend your time hunched over a computer keyboard, this can lead to pain and stiffness in your neck and shoulders.

It is the fourth leading cause of death due to non-communicable diseases.