What Happens to Your Body When You Sit for Long Periods of Time
Step away from that desk.
Updated Sep 20, 2018 1:40 PM
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Sitting for long periods of time is like adding water to a grease fire—it will only make things worse. But according to the American Heart Association, sedentary jobs have increased 83 percent since 1950, and studies have shown that the average American sits for 12 hours every day. Of course, this doesn’t mean you need to quit your day job ASAP, but it’s important to be aware of exactly how often you’re moving your body.
“The body is literally made to move,” says founder of Movement by Lara and physical therapist Lara Heimann. “It’s constructed of bones, muscles, soft tissues, and organs, all of which depend on movement to function optimally.” While Heimann says that people don’t have to exercise aggressively—too much endurance can be detrimental for some people’s health—it’s important to move as frequently as possible. “The body should be moving for some amount of time every hour,” she explains. “In other words, it’s better to move for 10 minutes out of a 60-minute interval than to be sedentary for eight hours and then move for one hour.”
Orthopedic surgeon and sports medicine specialist Dr. David Geier adds that while exercise is good, it’s even more important to incorporate low-intensity, steady-state activities, like taking leisurely walks and cleaning the house. “It’s not just important for current health reasons but to also live healthier lives later down the line,” he says. Here’s what really happens over time when you live a sedentary lifestyle.
After One Day
Truth be told, a lot can happen from just sitting at your desk for hours at a time. “After a bit of sitting, your postural muscles ‘dial down’ their firing power, so you will consequently sag into the seat,” says Heimann. “With each hour that goes by in a seated position, the decreased activation of the postural muscles—muscles around the axial skeleton, including ribs, spine, and pelvis—further impacts the limb musculature, resulting in decreased blood and lymph flow.”
You might even put yourself at risk for a cold. “Different studies reveal that sitting for as little as 30 minutes can start to affect the lymphatic system,” says Heimann. “The body needs to move for the lymph system to function, and the lymphatic system is responsible for our immune system.”
However, you can’t just blame your day job for being immobile. Dr. Geier explains that while it can be the main reason you’re sitting for long periods of time, sedentary activities like watching TV or playing video games can be harmful if they’ve become a replacement for healthier, movement-based activities.
After One Week
Whether you’ve had to skip the gym for a week or opt to stay at your desk more than you’d like to admit, you may begin to notice that your muscle tone might not be the same as before. “[This] affects how well your blood is circulated in the body. You will have diminished muscular power and endurance, as well as metabolic changes that place you at greater risk for preventable diseases like diabetes and heart disease,” says Heimann.
You may also notice that your muscles feel a little tight. “The connective tissue that is ubiquitous in the body—known as fascia—can become adhered to the surrounding muscles, creating a feeling of stickiness and rigidity.” So the next time you feel like the Tin Man from The Wizard of Oz, get up and go for a leisurely walk to get things moving again.
After One Month
“Being sedentary for one month is detrimental to all systems of the body,” says Heimann. “Not only will you lose muscle mass, but you’ll also lose bone mass and your cardiopulmonary efficiency will be diminished.” Continuing to sit for long periods of time can also negatively affect your nervous system, which can alter your mood, brain function, and energy levels, according to Heimann.
After Six Months
Between six months to a year, Dr. Geier states that these habits are harder to break, especially as you get older. While you might notice an increase of fat has appeared around your abdomen, these insidious changes occur slowly over time.
According to Heimann, being sedentary for this length of time can even age you by a year. “Without the necessary movement of the musculoskeletal system, all systems are negatively impacted and stressed, which has a detrimental impact on your overall health,” she says. “Being sedentary for that long is like being placed in a time capsule that skips ahead; it’s the equivalent of aging without reaping any of the rewards of memory or experience.” Guess we better start moving.