The average American does it for 10 hours a day. While this position may be so comfortable, it’s completely unnatural for the human body. Our body contains 640 muscles, 360 joints, 900 ligaments, and 206 bones, all specifically designed to aid in motion. And the reality is that sitting down can harm the body in many ways. How many ways exactly? Let’s talk about it.
How prolonged sitting damages the body?
One depressing fact – physical inactivity is the 4th leading cause of global mortality. Some people even say that “sitting is the new smoking!” When you sit down, your veins, nerves, arteries, internal organs, and muscles become compressed, negatively impacting many systems in your body. So, let’s talk about the impact on each system, beginning with the skeletal and muscular systems.
Impact of sitting on the skeletal and muscular system:
The spine contains 33 bones and 23 disks. Sitting causes the spine to curve, placing these discs and bones under unequal pressure. This causes them to become inflamed, and the muscles that support them are strained.
Sitting also causes rigidity in chronically short muscles, such as calves, the inner hip, and the hamstring. Some ligaments and joints also become overloaded, meaning they’re subject to more force than usual. Together, all of these muscle imbalances combined with the wear-n-tear on spinal discs are the number one cause of lower back pain.
Have you ever heard your colleagues or your friends in computer-centered occupations complain about this? Well, now you know why. It’s because people who work primarily on computers tend to spend about 87% or 7 out of 8 hours of their working day sat in chairs.
Impact of sitting on the respiratory system:
The skeletal and muscular systems are not the only ones impacted. The respiratory system is affected too. When sitting, the chest cavity’s size is reduced. This means that the lungs can’t expand as much during respiration. The result is that the amount of oxygen dispersed into the bloodstream is reduced as well.
Sitting increases abdominal pressure, the diaphragm muscle contracts against a higher pressure with inefficient complete excursion, therefore less air is inhaled. While sitting, the spine undergoes an aggravated thoracic kyphosis, leading to a forward rounding of the back. This curvature additionally limits the chest cavity, affecting the efficiency of both inhalation and exhalation in a portion of the lungs.
Impact of sitting on the digestive system:
Something similar takes place in the digestive system. Though research in this area is not conclusive, it kind of makes sense.
When sitting, there is less space to move food through the body since our internal organs are being compressed. Due to the lack of space, food passes through our 9-meter long digestive tract and gets digested more slowly than usual. And, on top of that, if digestion slows and abdominal muscles become too weakened from extensive sitting, it may even lead to constipation.
Impact of sitting on the respiratory system:
Sedentarism also harms the circulatory system. Just like with the digestive and respiratory systems, the various parts of the circulatory system become compressed when we sit down. When not compressed, smooth muscles in the vessel walls and the skeletal muscles normally move blood through the body, but persistent immobility interferes with the process.
Just 2 hours in a chair leads to a 20% reduction in good cholesterol, as well as a drop in lipoprotein lipase, which is an enzyme responsible for breaking down fat in the blood. So, sitting also dramatically slows down the rate at which the body can burn fat.
In addition, since arteries and veins become pressurized, after just 3 hours in a chair, arterial dilation reduces by 50%. This means blood vessels become constricted and blood flow gets reduced, causing limbs to swell.
Impact of sitting on the lymphatic, urinary, and nervous systems:
On top of all of this, the lymphatic and urinary systems are also disrupted. This is because sitting leads to the stagnation of blood and lymph in the pelvic area, creating favorable conditions for the development of pathogens.
Finally, let’s talk about how immobility impacts the nervous system. Just like structures in all the other systems we’ve discussed, nerves undergo compression when we’re sitting. This is physically noticeable in the form of numbness or tingling in the limbs, with the additional drawback of constraining the transmission of signals to and from the brain.
Furthermore, prolonged sitting can have adverse effects on the brain itself. Remember that reduction in blood flow that we mentioned earlier? The vertebral arteries provide 20% of blood flow to your brain. When sitting, the head tilts forward due to hamstring tightness and lumbar kyphosis, and the vertebral arteries become compressed. This leads to lower levels of oxygen in the brain, negatively affecting concentration levels and brain activity. So, if you get “brain fog” after sitting for an extended period of time, take a walk to increase blood circulation to the brain!
A bit about the modern lifestyle:
By the way, chairs were uncommon until the 16th century. And it’s only recently that sitting excessively has begun to cause problems for people on a large scale. And, according to the EPA, the average American spends 93% of their life indoors. 87% of time is spent inside buildings, and another 6% is spent in cars. That means only 7% of the average person’s life is spent outdoors! Only 7%, mind-blowing! And guess what? If you’re not outdoors, you’re much more likely to be sitting down.
So far we’ve discussed the immediate effects of sitting too long. But persistent lack of activity and extended periods of sitting can lead to devastating health risks, which include heart disease, diabetes, kidney problems, liver problems, and even some forms of cancer.
In fact, research has shown that sedentary behavior is consistently linked to more than 30 chronic diseases and conditions. Persistently immobile people experience a 100% increased risk of contracting type 2 diabetes and a 147% increased risk of contracting heart disease. The UCLA researchers have even shown that sedentary behavior is associated with thinning brain regions critical in memory and information processing.
Quite depressing, right? All of these consequences sound pretty severe, and they are. So what can we do to mitigate them?
How to mitigate sitting risks?
First, if you absolutely must sit, do so with correct posture. You might ask what defines correct sitting posture. Well, there are several qualities. First, weight must be symmetrically distributed on the left and right sides of your body. Then, weight must be offloaded symmetrically through the soles of the feet and through additional weight distribution points. On chairs, these additional points are the back- and arm-rests.
Next, you must respect the normal curvatures of the spine! If you want to impress your friends with some medical terminology, let them know that lumbar lordosis, thoracic kyphosis, and cervical lordosis should all remain within normal ranges.
Finally, the hips should also create a 90-degree angle with the rest of the body when sitting, and any screen or paper currently in use should be kept at an arm’s length, with a viewing angle right-at or just-below eye level.
Next, the ideal alternative is getting a standing desk to help you work in a totally upright position. Just get it, you’ll love it and thank me later!
Aside from sitting properly and getting a standing desk, you should also take regular breaks and move around, ideally every 30 to 45 minutes. Setting a reminder on your phone or Apple Watch is a great way to make sure you get it done. Finally, everyone should be incorporating exercise into their everyday routines, ideally in the mornings. Occasional exercise will not counteract the consequences of extended sitting, so try to work out as regularly as possible and avoid sitting for long periods of time.
