It’s no secret that Western countries, including the United States, have a problem with obesity. About 34% of adults and 15 to 20% of kids are obese in the U.S. alone. But there is another epidemic sweeping the nation. This is also a lifestyle disease. Some experts refer to this lesser known plague as “sitting disease” and it’s a growing problem. In fact, a 2008 study published in the American Journal of Epidemiology found that the average American spends almost 55% of the time they are awake sitting. We sit at work and then set when we get home, as we watch television or work in front of a computer.
Unfortunately, sitting this much has health consequences. Have you ever wondered what happens to your body when you sit too long in a chair?
Sitting Negatively Impacts Blood Vessel Health
Sitting reduces blood flow to your legs. In fact, one study found that even 10 minutes of straight sitting interferes with the ability of small arteries in the legs to expand. So, you get reduced blood flow to your legs and feet. Even worse, the reduction in blood flow boosts the risks of a blood clot forming. When blood clots form in the legs, there’s a small risk of one breaking away & traveling to the lungs where it can be fatal. That’s why it’s so important to move your legs throughout the day to maximize blood flow.
Dead Butt Syndrome
Sitting too much weakens the glute muscles. This is so common that there’s a syndrome named for it – dead butt syndrome. Since strong glutes are important for stabilizing the hips & pelvis, sitting a lot increases the likelihood of lower back pain. In fact, sitting too much weakens other muscles too, including the muscles in your core. That’s why strength training is especially important if you have a desk job.
Insulin Sensitivity Drops
Studies show that sitting reduces insulin sensitivity and contributes to insulin resistance. Insulin resistance is a major risk factor for type 2 diabetes & cardiovascular disease. One study found that women who sat for 8 hours daily, as many who have an office job do, had 56% greater odds of developing type 2 diabetes. On the plus side, even brief periods of activity to break up sitting enhances insulin sensitivity and lowers blood sugar. You don’t have to run a marathon to reduce the risks associated with sitting too much.
Sitting Too Much Raises the Risk of Cardiovascular Disease
Elevated triglycerides & higher blood sugar are both associated with a higher risk of cardiovascular disease. One study found that subjects who replaced two hours of sitting time with standing time enjoyed an 11% reduction in triglycerides and a 2% reduction in fasting blood glucose. The participants also experienced a rise in HDL-cholesterol. So, standing is better than sitting, but walking around as much as possible during the day is best.
Sitting is Bad for Brain Health
A study by researchers at UCLA found that sitting is linked with thinning in a portion of the brain called the medial temporal lobe, a part of the brain closely involved in forming memories. What’s more, subjects in the study who did structured, high-intensity workouts still had thinning in this region of the brain. So, structured exercise won’t make up for all the negatives of too much sitting. One of the most important things we can do for brain health is to move throughout the day and break up periods of sitting.
Negative Impact on Mood and Energy Level
Have you ever noticed that you feel tired when you sit too long? It’s not your imagination. A study of 30 adults found that those who did micro-sessions of exercise throughout the day, consisting of around 5 minutes of exercise, reported improvements in energy and mood and experienced fewer food cravings.
Sitting is associated with a higher risk of mortality in general. A study found that women who sat for more than 6 hours daily were 94 % more likely to die during the study relative to those who sat fewer than 3 hours daily. According to the American Cancer Society, more hours of sitting is linked with a higher risk of death due to Alzheimer’s disease, Parkinson’s disease, stroke, heart disease, diabetes, kidney disease, lung disease, cancer, liver disease, and suicide. That covers a lot of territory!
The Bottom Line
More movement, less sitting is the take-home message. You may not be able to run in place, jump rope, or do high knees at work, but you can take more walking breaks. Even better, head for the stairwell and climb a few flights of stairs. When you’re confined to your seat, stretch and flex your calves to keep the blood flowing to avoid blood clots. You’re at higher risk of blood clots if you use hormonal therapy such as birth control pills or hormone replacement therapy. Keep that in mind. Also, make sure you’re drinking lots of water to reduce the risk of blood clots.
The good news is research shows that even short exercise breaks help to reduce the negative effects of sitting. It’s not enough to do a structured workout. Prolonged sitting is an independent risk factor for health problems and premature mortality. So, don’t keep your bottom line glued to a chair. A standing or even a treadmill desk works for some people. But, whatever you do, keep moving!
UHN Daily. “Benefits of Standing vs. Sitting for Cholesterol and Triglyceride Control”
Int J Behav Nutr Phys Act. 2016; 13: 113.
Science Daily. “Simple leg exercises could reduce the impact of sedentary lifestyle on heart and blood vessels”
WebMD.com. “More Evidence Too Much Sitting Raises Clot Risk”
Diabetes Care. 2012 May; 35(5): 976–983.
InBodyUSA.com. “5 Ways Sitting All Day Wrecks Your Body Composition”
Science Daily. “Sitting is bad for your brain — not just your metabolism or heart”
American Cancer Society. “Sitting Time Linked to Higher Risk of Death from All Causes”
Psychology Today. “What Sitting Does to Your Psyche”