Is Sitting Really the New Smoking?
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Born to be Lazy?
If you read these words, seated in a chair or lounging in bed and feeling guilty about your laziness, take solace in knowing that your current state of physical inactivity is an ancient, fundamental strategy to allocate scarce energy sensibly.
You know that exercise is good for you. Nevertheless, when you can choose between the escalators or the stairs in a building, you most probably choose the ones that move for you. And how often do you drive around a parking lot several times looking for the closest spot rather than park farther away and walk the relatively short distance?
That is because your instincts are always to save energy.
For most human evolution, that didn't matter because if you wanted to put dinner on the table, you had to work really hard.
However, today machines and technology make our lives easier. We live in a world that encourages physical in-activity, and because the instinct to avoid non-essential physical activity has been a pragmatic adaption for millions of generations, we haven't adapted our basic instincts to that situation.
So, if you made it to the gym today, you may have overcome powerful evolutionary forces. If you didn't, blame biology.
Exercise is something humans never evolved to do (but is healthy nonetheless).
Read on and get the scientific facts as to why sitting is both very normal, but also can be really bad for you, why muscles are more impressive than you might give them credit for, plus what to do if you have to sit a lot every day.
How Did I Get So Clever on the Sitting Business?
I read Daniel E Lieberman's great book Exercised, which is a book about the science of physical activity, rest, and health.
Daniel E Lieberman is a professor of human evolutionary biology at Harvard University. He divides his time between field research in isolated, hunter-gatherer communities and his lab, where he studies human and animal physiology for clues to our evolutionary inheritance.
This post is build on Daniel Lieberman's research.
Sitting is so Natural
We, humans, sit a lot and always have.
Hunter-gatherers were/are rarely physically active unless they play, dance, or collect food.
Today's typical hunter-gatherer adult (like the Hadza, who live in the dry, hot woodland of Tanzania in Africa) spends 3 hrs and 14 minutes doing light activities and 2 hrs and 14 minutes doing moderate or vigorous activities.
On average, the Hadza women walk 5 miles a day and dig for several hours, whereas the men walk between 7-10 miles a day. And when they aren't being very active, they typically rest or do light work - sitting. 1)
Although this activity level makes them 12 times more active than the average European or American, it’s by no means a backbreaking workload.
If you compare yourself to the animal we descendant from in a way - the chimpanzees. Even sedentary Europeans and American couch potatoes are wildly more active than them.
Chimpanzees spend most of their day either feeding or digesting. They typically devote about half their waking hours to filling their stomachs with highly fibrous food, and for much of the rest of the day, they rest, digest, groom each other, and take long naps. 2) They climb only about a hundred meters and walk just two to three miles on an average day. 3)
So Is sitting Good or Bad?
Yes it is. Both.
We've so demonized being a couch potato that sitting is called "the new smoking." But as stated above, modern-hunter gatherers sit about 10 hours a day, just as much as most people in the Western world.
Sitting is so ordinary. Sitting is less tiring and more stable than standing.
Although we evolved to sit a lot, we didn't evolve to sit motionless for hours on - sitting is indeed a problem if that's all you do.
Here is why.
The 3 Major Reasons Long Periods of Uninterrupted Sitting is Bad for You
Understanding the below got of the couch…
1. Sitting is Fattening
Sitting slows the rate we take up fats and sugars from the bloodstream.
Up to four hours or so after a meal, the body is in a postprandial state. This means that you're still digesting that food and transporting its constituents fats and sugars into the blood.
Moving, even moderately, your body's cells burn these fuels more rapidly. However, if you spend a lot of time sitting, your digestion is not as efficient.
Whatever fat and sugar you don't use, get stored as fat - and not just belly fat.
2. Sitting Elevates the Levels of Organ Fat
Long periods of uninterrupted inactivity harmfully increase levels of organ fat.
Most fat is healthy, but obesity can turn fat into an inflammatory foe.
In healthy, normal human adults, fat constitutes about 10-25% of the body-weight in men and 15-30% in women.
There are two major fat types:
I. Subcutaneous fat
90-95% of that fat is stored in billions of cells right under the skin in buttocks, breasts, cheeks, etc. These fat cells help us cope with long term shortages of calories, and they help regulate appetite and reproduction.
II. Organ fat
Fats stored in cells in and around our bellies and organs like the heart, liver, and muscles are dynamic participants in metabolism. When activated, they quickly dump fat into the bloodstream.
Organ fat in moderate quantities (about 1% of total body weight) is beneficial as a short term energy depot when we need rapid access to a lot of calories, such as when we walk or jog a long distance.
The body has a finite number fat cells.
If we store normal amounts of fat, our fat cells stay reasonably sized and harmless, but when fat cells grow too large because of obesity, they distend and become dysfunctional like an overinflated garbage bag.
Swollen organ fat cells are generally more harmful than subcutaneous fat cells because they are more metabolically active and more directly connected to the body's blood supply.
When organ fat-cells swell, they ooze a great many of the protein cytokines into the bloodstream, which incites inflammation.
Too much sitting, too many calories, and stress can in otherwise healthy people in less than two weeks add more organ fat and exhibit the classic signs of chronic inflammation, including less ability to take up sugar after a meal. 4)
3. Sitting Can Trigger Chronic inflammation
Swollen fat cells, too much fat and sugar in the bloodstream, stress, and inactive muscles are some of the mechanics that inflame us.
The biggest causes of chronic inflammation are: Smoking, obesity, overconsumption of certain pro-inflammatory foods (like red meat and refined sugar), and PHYSICAL INACTIVITY.
What is inflammation?
When your immune system detects a harmful pathogen, something noxious, or a damaged tissue, it reacts with inflammation.
Whether the offenders are viruses, bacteria, or sunburns, the immune system quickly launches an armada of cells into battle.
These cells discharge a barrage of compounds that cause blood vessels to dilate and become more permeable to white blood cells that swoop in to destroy any invaders.
This extra blood flow brings critically needed immune cells and fluids, but the swelling compresses nerves and causes the four cardinal symptoms of inflammation (which means "to set on fire"): redness, heat, swelling, and pain. Later, if necessary, the immune system activates additional defense lines by making antibodies that target and then kill specific pathogens.
Chronic low-grade inflammation
Chronic low-grade inflammation is like having a never-ending cold so mild you never notice its existence.
But it's there, and it affects the immune system tremendously.
Mounting evidence indicates that this slow burn steadily and surreptitiously damages tissues in our arteries, skin, muscles, liver, brain, and other organs.
In the last decade, chronic inflammation has been strongly implicated as a significant cause of dozens of noninfectious diseases associated with aging, including heart disease, type 2 diabetes, and Alzheimer's. Also, colon cancer, lupus, multiple sclerosis, and just about all conditions with the suffix "-itis" including arthritis.
As mentioned above, our cells pump tiny proteins termed cytokines into our bloodstream. Cytokines regulate inflammation by turning it on and off.
Cytokines can ignite short-lived, intense, and local inflammatory responses following an infection, BUT they can also stimulate lasting, barely detectable inflammation levels throughout the body.
Instead of blazing acutely in one spot for a few days or weeks to fight a cold, inflammation can smolder imperceptibly in many parts of the body for months or years.
By remaining inert for hour upon hour, our bodies never extinguish that faint inflammatory fire that may be smoldering in the background.
But there's hope because getting out of that chair will help you immensely.
How Exercise Combat Chronic Low Inflammation
You can eat a lot of anti-inflammatory foods, but that won't put out all the fire.
The best way to boost your immune system and combat chronic low-grade inflammation in your body is to flex those muscles.
Muscles function as glands, too, synthesizing and releasing dozens of messenger proteins called myokines. Among other stuff, myokines help control inflammation as they induce anti-inflammatory responses with each bout of exercise.
During moderate- or high-intensity physical activity, the body first initiates a proactive inflammatory response to prevent or repair damage caused by the exercise. Subsequently, it activates a second, larger anti-inflammatory response to return to a non-inflamed state.
Because the anti-inflammatory effects of physical activity are almost always larger and longer than the pro-inflammatory effect, and muscles make up a third of the body, active muscles have potent anti-inflammatory effects.
Even modest levels of physical activity dampen levels of chronic inflammation, including in obese people.
What To Do If You Have To Sit a Lot
Leisure-time sitting is far more strongly associated with poor health outcomes than work-time sitting. So, if you sit a lot during work but also sit a lot in the mornings, evenings, and on weekends, all that sedentism is going to be a problem.
There is compelling evidence that it's helpful to interrupt your sitting regularly.
Fidget
If you are working at a desk, get up every once in a while, fidget, go get yourself a cup of tea, whatever.
I, too, sit and stare at my computer screen a lot. So I've implemented a routine where I set my phone alarm to ring every 25 minutes. When the alarm goes off, I get up, do a minimum of 10 squats, and then some eye exercises. Sometimes I just go and make a cup of tea…
Those regular, frequent interruptions turn on your muscles and other aspects of your metabolism just enough to lower blood sugar levels and fat and counteract other negative effects of being sedentary. It's a bit like turning on your car engine.
Stand
Studies that compare the energy spent standing with that spent sitting report that standing costs about 8-10% more calories. For a 175 pound adult, this difference is a modest 8 calories per hour (=a slice of an apple).
Over time these calories could add up, though - to an extra 16000 calories a year!
Go for a Walk after Meals
A walk after having a meal uses the excess glucose present in the blood, thereby controlling sugar levels, it increases fat burn and improves digestion.
If you walk for 15 minutes after your lunch break, and for 15 minutes after your dinner every day, then you would have achieved 3.5 hours of walking in a week. If you also walk 15 minutes in the mornings, then you would reach more than 5 hours of walking in a week.
All things considered...
It's unhelpful to equate sitting with smoking. Unlike smoking, it's perfectly normal to sit. It shouldn't be a source of shame to use a chair, and a standing desk isn't a substitute for exercise. Just don't spend all your day in a chair. But who doesn't know that?
Keep moving it too.
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Disclaimer:
This blog's information is strictly for informational purposes only and should not be taken as medical advice. The Danish Health Authority has not evaluated the statements made in this blog. The products linked to in this book and any information published on this blog are not intended to diagnose, treat, cure, or prevent any disease. The information provided by this blog is not a substitute for a face-to-face consultation with your physician and should not be construed as medical advice. The entire contents of this blog are based upon the opinions of Hanne Robinson. By reading and using this blog, you agree to only use this publication for personal informational use and not as a substitute for medical or other professional advice.
Sources:
https://onlinelibrary.wiley.com/doi/abs/10.1002/ajhb.22919
https://www.pnas.org/content/108/35/14555
Jane Goodall, The Chimpanzees of Gombe: Patterns of Behavior
https://pubmed.ncbi.nlm.nih.gov/18349087/
Exercised by Daniel E Lieberman