Sitting. Whether it’s at work, school, driving or watching TV, can’t avoid it. Many of us spend a fair amount of time sitting. And sitting for long periods can affect your health and increase your chances of an early death. That’s why guidelines recommend sitting less. So what can you do to combat sitting?
It’s reported the average person sits more than 6 hours per day. And the amount we sit has been increasing throughout the years. In 2016 adults in the US sat for one hour more per day than they did in 2001. This is similar to what’s reported in other countries. However, these studies to assess sitting time and likely underestimated how much sitting we do. When compared to directly measuring sitting time (using wearable devices), surveys miss about 1.7 hours of sitting. So, it’s more likely the average person sits close to 8 hours per day.
What happens when you sit?
Sitting requires less energy than pretty much every other activity you can do. For a 150 pound person, an hour of sitting uses about 68 calories. Most of these calories are used to keep your body functioning. Standing may burn an additional 10% to 20% of calories. In contrast, walking for an hour uses around 300 calories.
As a result, your metabolism slows down when you sit. Much like the car that turns off its engine at a stop light. Enzymes (proteins that are needed for chemical reactions) that break down fats and glucose in the blood shut down. This leaves fats and glucose to circulate in your blood stream. While you need a certain amount of fats and glucose in the blood, too much can increase your chances of getting diabetes, heart disease, cancer and early death.
Long periods of sitting can also lead to muscle and joint stiffness. This is due to a slowing down of blood flow to your muscles. Since your muscles aren’t active when you sit, they don’t need as much blood. This reduces the supply of oxygen and other nutrients muscles need to keep active. Similarly, your joints may also get stiff from lack of movement. Increased sitting is also associated with low back pain and can decrease lumbar disc height. And joint stiffness from sitting is usually worse for people who have arthritis and other joint problems.
The Health Consequences of Sitting
Sitting for hours each day can increase your chances of getting a number of diseases. Our research found sitting for more than 8 hours per day was associated with a 20% greater chance of heart disease and early death compared to sitting less than 4 hours per day. And the chances of dying from cancer also increases with greater time spent sedentary (which is mostly sitting but can be other activities with minimal movement).
Sitting can also affect how you think. Research indicates increased sitting may contribute to changes in the brain associated with poor memory. And greater time spent being sedentary may increase your risk for cognitive impairment, dementia and depression. Some of this may be linked to lower amounts of physical activity, which is known to reduce risk for dementia and depression.
How to combat sitting?
Sitting isn’t going to go away. Nor should it. There are many activities that are much easier, and more comfortably done, when sitting. But we should limit how much we sit. And when we do sit, it’s good to take short breaks from sitting, as it’s long bouts of uninterrupted sitting that’s the most problematic.
There’s the notion that if sitting is bad, then standing must be better. This has led to a flurry of people buying standing desks. But standing for long periods comes with its own problems such as back pain, and varicose veins. Standing also doesn’t seem to alter the effects of sitting on fats and glucose in the blood. What’s really needed is movement. And movement throughout the day.
Regardless of how much sitting you do, being active can lower your chances for early death. However, even in people who are active, higher levels of sitting are associated with a shorter lifespan. A recent study suggested that getting at least 22 minutes of moderate-vigorous activity every day, was enough to offset the detriments of sitting.
Reduce Your Sitting and Increase Your Activity
Replacing sitting time with being active, may be the best way to maintain your health. You can do this by taking activities you usually sit doing and get moving. This can include walking meetings (either at work or for socializing), standing up and pacing while on the phone, and being active during TV commercial breaks.
If you know you may be sitting for a while on a task, set your phone alarm to go off every 20-30 minutes to remind you to get up and move. You can use this to get in a 1-2 minute exercise snack such as walking in place, jumping jacks and push-ups. Even light activity can reduce your blood glucose and relieve your muscles and joints compared to continuous sitting. It can be as simple as choosing a bathroom on a different floor, or printing to a printer further away. Anything that works for you to get in a bit more activity and a bit less sitting.
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