Humans are not meant to sit as much as we do. We evolved to be naturally moving all day long, not to live today’s sedentary, comfortable, inactive lifestyles. Even if you’re doing the recommended two and a half hours of exercise a week, that’s not enough to counteract the effects of a sedentary job.
Thirty minutes of exercise before or after work doesn’t combat the effects of sitting at a desk all day and you are still classed as having a sedentary lifestyle. Inactivity is now a bigger killer than obesity.
We need to move our bodies regularly and frequently throughout the day, and that means every 30 minutes. Dr David Agus, a leading cancer specialist and innovator, says sitting for five hours is the equivalent of smoking more than a packet of cigarettes in terms of increased risk of cancers, heart disease, diabetes and other conditions.
It was Dr James Levine who coined the phrase ‘sitting is the new smoking’. He is director of the Obesity Solutions Initiative at Mayo Clinic-Arizona State University, and invented the first treadmill desk.
He says: “Sitting is more dangerous than smoking, kills more people than HIV and is more treacherous than parachuting. We are sitting ourselves to death.”
All the data and research, says Dr Agus, shows that we need to stand up and move around for four to five minutes every 30 minutes. Other, smaller studies say that every 20 minutes we should at least stand up, for one to two minutes.
It’s all to do with how our metabolism works when we’re sitting, standing or moving around. When we’re standing up the body is using energy very differently to when it’s sitting, or to when it’s exercising.
It’s burning calories at a different rate, storing them in different ways, and our brains are functioning differently. Muscles in your legs and back contract, which increases production of certain enzymes that break up fat in the blood stream.
When you’re moving around, the body is using up energy for the cells to carry out basic functions and movements. But when you’re sitting, the body is not using calories, fat is building up, and it gets increasingly difficult to get up off your chair and do something.
How sitting vs standing affects your metabolism
Our body’s metabolism has three components, or three ways it uses energy to maintain itself: 60 per cent of your metabolism is the basal metabolic rate (BMR), carrying out the basic, essential functions of the tissues, cells and organs. You burn this energy even while lying down or resting.
Ten to 15 per cent is the thermic effect of food (TEF), breaking down and digesting food. And 25-30 per cent is non-exercise activity thermogenesis (NEAT), the fat and calorie-burning activity of daily life, such as getting dressed, walking, going up stairs, using your phone or cooking a meal.
It’s different for everyone, but standing can burn 50 calories an hour more than sitting. If you have a desk job, you’re only using around 300 calories a day on NEAT, whereas someone with a job where they’re moving around may use up to 1,300 more.
Hence if you’re the boss or CEO diligently making time for strenuous tennis lessons or expensive personal training sessions you may actually be way less healthy than the plumber who turns up to fix a leak or the barista serving you your morning latte.
If you’ve been harbouring an urge to quit the rat race and become a gardener, artist, therapist or follow a non-office-based passion, perhaps your health will be the impetus you need.
Talk to your parents about this, too: older adults (65 and over) are the most sedentary population group, with many sitting for ten or more hours a day. Agree with them simple changes they can make to their day.
Six reasons why you shouldn’t sit all day
Here are six ways research has shown that sitting is harming your health.
1 Obesity. One study found that when 1,000 calories was added to participants’ daily food intake, and none was allowed to exercise, those who were sedentary gained weight and those who moved around during the day maintained the same body weight.
2 Diabetes. After you eat a meal there’s a rise in your blood sugar level, which peaks after about an hour. If you’re immobile, your body has no activity to use up that energy (glucose) on. It turns into fat.
By just going for a walk after eating, that glucose is used up. And the more that gets used, the less there is to turn to fat, and eventually contribute to weight gain, obesity and diabetes.
A major review of 18 studies with a combined 800,000 participants found that those who sat the most were twice as likely to develop diabetes as those who sat the least; they had a 112 per cent increased risk of the disease.
3 Depression. Sitting reduces your circulation, making it harder for feel-good hormones to reach the brain’s receptors. This study of 9,000 women aged 50 to 55 found that those who sat longer suffered from depression at much higher rates than the women who sat less. Women who sat for more than seven hours a day were 47 per cent more likely to be depressed than those who sat for four hours or fewer.
4 Earlier death from heart disease. A 14-year study of 120,000 men and women found a higher rate of mortality, particularly from cardiovascular disease, among those who sat a lot than those who didn’t. People who sat for more than six hours a day died earlier than those who sat for three hours a day or less.
5 Cancer. Those who sit for too long are at 24 per cent greater risk of developing colon cancer, 32 per cent greater risk of endometrial cancer and 21 per cent of lung cancer. That was the result of a 2014 review of 43 studies covering four million people and 68,936 cancer cases – and that was regardless of how much exercise those with sedentary lives were doing.
6 Muscular problems. Muscles need to be moved and flexed to stay healthy. If they’re not, they become stiff and unhealthy. If they sit all the time, they get used to sitting. Then standing, walking, running, dancing and exercising all become harder. So use them or lose them.
Do you have a desk job? Here’s what to do
You need to increase your metabolism, specifically activity thermogenesis (NEAT), which means that simple changes to your day are enough to make a big difference.
Wash the dishes instead of loading the dishwasher. Get up to change the TV channel instead of pressing the remote. Watch less TV (or at least get up during the ads). Go out or walk the dog instead of spending the evening on your laptop.
Use the stairs instead of the lift at work, for example. Walk up the escalator in tube stations and shops. It never ceases to amaze me how many young and able people stand on the escalator at Oxford Circus station in the morning rush hour. Like zombies on a conveyer belt. What lazy bones!
In the office, get up for a drink of water. Walk around, maybe down a corridor or up the stairs and back (you get the added bonus of a screen break). After lunch, especially if it’s lunch at your desk, go for a ten-minute walk.
Go to talk to a colleague in the office instead of emailing your comment or question. Have standing meetings. Have walking meetings: instead of grabbing a meeting room or a breakout area for that update or discussion of an idea, walk around the block together.
When you are sitting, move your legs, such as circling your feet to get the circulation moving, point and flex your toes, or stretch the arms up and twist from side to side.
Change from a sitting desk to a standing one. You could burn an extra 500-1,000 calories a day.
Or get a treadmill desk, maybe starting with one in the office that everyone takes a turn on. Dr Agus has one and spends around two hours a day on it, dealing with emails (easier than it sounds, as they only move at about 1mph).
Dr Levine says: “In the same way that standing up is an oddity now, sitting down should be. We need to change the default: I want us to have to find excuses to be sitting down.”
Jacqui Gibbons is editor of our health channel, edits beauty and lifestyle features, and writes about health trends. Follow her on Twitter: @jacqui_journo