Why sitting all day is worse for you than you think - and what to do about it
- Michelle Adams
- Mar 20
- 10 min read
Updated: Mar 20
You can listen to the video version of this article here.
If you are sitting down or laying in bed while reading this article, then I challenge you to get up and get moving as you scroll down this page. That's right, we are combining reading and movement today, feeding both the mind and the body. You can get some steps in, do some planks, or maybe even some squats. If you are using a desktop computer, don't worry - you can make your movement periodic. How does a squat after each paragraph sound? Fun, right?
You’re here because you want to start moving more, but you need a little nudge, a bit of motivation, a little gas in your car to get you on your way to doing what you know you need to be doing. Maybe you used to exercise before, and you stopped because life happened; you started school, you moved, got a new job, became a parent - any of these major life changes can cause your daily routine to change completely. Or, maybe you are starting out for the first time and growing up, you never really had anyone to guide you or help you to even see the value of exercising. But, now that you’re grown, you’re looking to break cycles and become a better version of you. You may even be a seasoned, active exerciser, who is here because you want to understand the scientific benefits behind the good habits that you have already mastered. No matter where you are on your exercise journey, there is something in this article for you.
Today, I will be talking about movement and more specifically, how not moving enough changes your body on a biological level. I’ll also talk about how much movement you actually need to counteract these changes. You will be surprised at just how little activity you need to do to keep your body in a good state of health. Also, if you have ever wondered if the headline that being sedentary or sitting too much is as bad as smoking, I will address that claim towards the end of the article.
First, let’s talk about how sitting changes your body at the cellular level.
When you are in the sitting position, your skeletal muscles are not doing much contracting. That’s because sitting is easy – your muscles don’t have to do much work, so they can just chill. This is why plopping down on the couch at the end of a long day of being on your feet feels so good – your muscles can finally be at ease.
Sitting in and of itself is not bad. The problem arises when you let Netflix auto-play episode after episode of whatever hour-long drama you are currently wrapped up in, and you end up in the same position for hours.
You told yourself that you would watch just an hour, but the acting and cinematography are far better than you had anticipated.
As the storyline unfolds, your body produces less and less of the enzyme lipoprotein lipase or LPL. LPL is important for clearing out fat from your bloodstream. Without enough LPL, you can end up with high cholesterol and high triglycerides. Less LPL is also associated with less HDL – your good cholesterol – and higher blood sugar.
Changes at the cellular level lead to changes on the organ and whole body level, which in turn become diagnosable and sometimes fatal illnesses. Here is a summary of all of the negative health outcomes that have been linked to sitting for 2 or more hours at a time (See here, here, here, and here. Note: some studies used a minimum of 2 hours, others used 4 hours):
Poor blood sugar control and a higher risk of type 2 diabetes
Higher waist circumference
Higher triglycerides
Higher total cholesterol
Lower HDL cholesterol (this is your "good cholesterol")
Higher blood pressure
A higher chance of dying from heart disease
A higher chance of dying from cancer
A higher chance of having a shortened life span
Have you gotten up yet?
When you consider how easy it is to spend 2-4 hours a day sitting uninterrupted while working, commuting, or streaming, it becomes easy to see just how significant the impact of sitting can be on our lives.
In terms of the magnitude of these effects, the risk for developing type 2 diabetes is doubled in people who spend hours and hours sitting, while the increase in risk for dying from heart disease, cancer, or some other cause falls between 10-20%.
Let’s talk more about how sitting increases your risk for diabetes.
Sitting is bad for blood sugar control, mainly because of its impact on how your body metabolizes carbohydrates, or carbs.
Let’s do a quick side bar on carbs. Carbs are basically long chains of sugar molecules. Bread, cookies, fruit, potatoes, juice – these are all carbs. When we digest carbs, they get converted into sugar. Now, for our bodies to use that sugar, the sugar must first enter our cells. Sugar doesn’t just waltz into our cells though – it needs a special key, and a special door. Insulin acts as a key to unlock the door to the cell. As for the door itself, that is called a glucose transporter (GLUT).
Our bodies get prompted to make more glucose transporters, the doors to the cells, when we move. Exercise, even at low intensity, has been shown (here, and here) to dramatically increase the content of GLUT4 in muscle. Basically, movement makes our bodies more efficient at keeping blood sugar levels stable.
Exercise doesn't just help to grow your muscles - it literally changes how your muscles behave.
The last side effect of sitting for most of the day that I want to mention is worse bone health.
Yep, sitting is bad for your bones.
Sedentary behavior is linked to lower bone mineral density. This is kind of a “use it or lose it” situation – studies on people who spend long periods of time in space and people confined to the bed by spinal cord injuries tell us that when we are not bearing weight on our bones regularly, they respond by getting less dense. More bone gets broken down, which may lead to an increased risk of osteoporosis.
What about if you work out a fair amount but still spend most of the day sitting?
Now, I know that someone out there is wondering:
“What if I workout several times a week, but I have a job where I have to sit for most of the day? Do I still need to worry about any of this stuff?”
If this is you, then you are what has been called an “Active Couch Potato.”
The bad news is that yes, you could still be at risk for a host of health problems, and we know that thanks to this study, where researchers studied over 4000 men and women who reported exercising for at least 2.5 hrs per week and found that the people who sat the longest in front of the TV were most likely to also have a higher waist circumference, high blood pressure, and worse blood sugar control. I will say that this association was correlational, not causative as this was not a randomized controlled trial.
To counteract the effects of sitting too much on your health, you would need to do 60-75 minutes – that’s an hour or more – of moderate exercise every day. It can be tough to even do 30 minutes of exercise a day, so an hour of moderate-intensity exercise every day is not impossible, but does fall into the realm of what I would consider unrealistic for most people. It may be more feasible to just find ways to break up extended periods of sitting with some sort of movement throughout the day. What’s more, is that even if you are able to work out for an hour or more per day, you still won't be completely off the hook. If you spend >5hrs a day sitting, you will still have a higher risk of dying sooner than people who exercise often but spend less time sitting.
Now, onto the final topic:
Is sitting really the new smoking?
Starting over a decade ago, headlines claiming that sitting was as bad or nearly as bad as smoking started to pop up across the internet. The LA Times, TIME, and the Mayo Clinic all posted on this topic, along with other less known health media pages (like this one, and this one). I want to make it clear that this is not true. While sitting for too long is bad for you – smoking is much, much worse.
This paper compares the data on health outcomes related to both smoking and too much sitting and shows that the two are clearly very different in terms of the harmful outcomes that they are likely to produce.
Let’s do a comparison.
Sitting for too long has been shown to increase your risk of dying sooner by 22%. On the other hand, smoking is associated with a 180% increased risk of dying. Smoking causes far more deaths overall than sitting. Smoking kills people by causing lung cancer, but what you may not know is that smoking also increases your risk for heart failure, chronic obstructive pulmonary disease (COPD), diabetes, reproductive issues, and several types of cancer, not just lung cancer.
So now, what do we do? Let’s talk solutions.
No, I’m not going to say to just exercise. More exercise is a good idea for most people, but as I mentioned before, you would have to do a ton of exercise to outdo the effects of prolonged sitting. Instead of trying to undo the effects of sitting, it may be better to just balance the two. The key here is to not sit for hours and hours at a time. My main solution is – don’t be afraid to be weird. If your job requires you to be seated all day, get up every 1-2 hrs or even every 30 minutes if you can, and try to work while standing, or take a walk, or do some squats. While streaming, take breaks in between episodes and get up and do something. Make it something fun that you look forward to. If you live with other people, you can compete to see who can do the most jumping jacks, or who can do the most pushups.
Research shows that just 5-10 minute bites of movement is good for your health. Yes, you read that right - just 5-10 minutes. Benefits of bite-sized workouts include:
Improved cardiorespiratory fitness,
Higher levels of "good cholesterol" (HDL) and lower levels of "bad cholesterol" (LDL) and triglycerides
Healthier weight
Improved blood pressure
Better blood sugar levels
Reduced inflammation (as measured by C-reactive protein, or CRP)
A longer life
So, choosing to take the stairs, or parking in a spot that is far away from the grocery store entrance, or asking your employer for an adjustable desk that lets you stand or sit while you work are all worthwhile. These are just some ideas, but how you choose to add more movement to your day is entirely up to you.
Alright, that's all for today. Take care!
References:
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Headlines: Is sitting the new smoking?
Chandler, M. Repost: Sitting is the New Smoking. Mayo Clinic. Published February 16, 2021. https://connect.mayoclinic.org/blog/living-with-mild-cognitive-impairment-mci/newsfeed-post/repost-sitting-is-the-new-smoking/
Oniyide M. Sitting is the New Smoking: The Health Risks of Sitting and Minimizing Those Risks. RWJBarnabas Health. Published November 16, 2022. https://www.rwjbh.org/blog/2022/november/sitting-is-the-new-smoking/
Park A. How Sitting Is Killing Us. TIME.com. Published September 2, 2014. https://time.com/sitting/
Ravn K. Don’t just sit there. Really. Los Angeles Times. Published May 25, 2013. https://www.latimes.com/health/la-xpm-2013-may-25-la-he-dont-sit-20130525-story.html#:~:text=%E2%80%9CSitting%20is%20the%20new%20smoking
SHN Staff. Sitting for long periods causes health problems. Sanford Health News. Published February 9, 2023. https://news.sanfordhealth.org/heart/sitting-is-the-new-smoking-truly-a-silent-killer/
Taking 5-10 minute breaks is worth it!
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Image source: Good Samaritan Hospital, Westchester Medical Center Network
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