Excessive sitting is likely damaging your health—whether you exercise regularly or not. Sitting has been referred to as the the new smoking. A recent study shows that risk of death begins to rise if bouts of sitting persist for longer than 10 minutes at a time.
So, how do we reverse the trend toward laziness? This question preoccupies me as a cardiologist and senior scientist with the Toronto Rehabilitation Institute and University Health Network. In my clinical practice, I help patients receive appropriate medical therapies to improve their quality of life and longevity. But physical activity is one therapy I cannot prescribe as effectively.
One solution is to think of physical activity as a “pill.” As with other medical prescriptions, this “pill” requires a preparation, a quantity, and a strength.
To know how much to take, we must monitor our behaviors. We must count the number of minutes we do moderate to vigorous physical activity per week. We must also count the number of hours per day we remain sedentary, and the number of minutes we remain sitting at any one point.
What’s Wrong With Sitting?
We know that physical inactivity has a significant impact on our health. A recent study examining more than 130,000 patients from more than 17 countries estimated that 1 in 12 deaths could be prevented if everyone exercised 30 minutes per day, five days per week at moderate intensity.
Exercise prevents many chronic diseases, including heart attacks, strokes, diabetes, and cancer. It improves our cardiopulmonary fitness levels—a measure of how efficiently oxygen is extracted from the blood and into organs and tissues throughout the body—and is linked closely to our overall health and survival.
Evidence suggests that sitting times and sedentary behavior have important impacts on health regardless of physical activity levels. For example, a recent review by our team found that sedentary times of six to nine hours or more per day are associated with a higher risk of death, cancer, and cardiovascular disease. The greatest risks are linked to Type 2 diabetes. Moderate physical activity only partially reduced the risks.
The duration we sit at any one time may also count against our health. Patients who sit for prolonged periods burn fewer calories than those who stand or move frequently throughout the day. Insufficient calorie expenditures may result in excessive fat, which may be toxic to our metabolism. Such toxicity can give rise to chronic diseases such as obesity, diabetes, cancer, and heart disease.
In sum, while moderate to vigorous physical activity may improve our fitness levels, sedentary behavior may accumulate calories and fat. Each behavior affects our health and survival in different ways.
Laziness a New Trend
As humans, we are primed to move. One needs only to look at babies and toddlers, who rarely stay still once they have acquired the skills to crawl and walk. To explore their environment, they need to move.
Then, at some point, a child becomes more sedentary. Perhaps through their first exposure to TV, their first video game, or their first internet search, children realize that their quest for self-discovery need not involve movement. The seeds of the disease known as physical inactivity are planted, with devastating physical and psychosocial health impacts.
Of course, things weren’t always this way. We were once hunters and gatherers. This necessitated high amounts of physical activity throughout the day just to procure water and food for survival. It has been estimated that between 25 to 35 percent of the total energy consumed by our ancestors was through physical activity.
Contemporary humans burn much less of their total energy through physical activity. Even when compared with highly agricultural societies, the physical activity levels of most modern adults pale by comparison. For example, one study demonstrated that the average American’s daily steps are less than half that of older order Amish communities.
Perhaps not surprisingly, the decline in physical activity levels over the last several decades has come from nonrecreational physical activity, such as work. Most alarming has been the dramatic reduction in physical activity among youth and adolescents.
If this trend continues, we are looking at a bleak future.
Strategies to Help
How to reverse this trend? Assuming that optimal health requires patients to both undertake physical activity and avoid excessive sedentary behavior, the solutions seem intuitive: Move more, and sit less.
To avoid sitting yourself to death, you can follow some simple strategies:
- Take frequent standing or walking breaks.
- Limit sitting episodes to under 30 minutes (particularly at work).
- Take 10,000 steps or more per day.
- Engage in 150 minutes of moderate to vigorous physical activity per week.
- Engage in resistance (strength) training two days per week.
Strength training improves muscle mass and resting metabolism, minimizes weight gain, and helps prevent osteoporosis.
While humans are primed to move, urbanization, technology, and societal norms have resulted in our physical stagnation. We have become sedentary, physically inactive creatures. But the solution may be as simple as counting.
As I sit here, I am reminded by my cellphone alarm that my 30 minutes of uninterrupted sitting is up. I ask my 9-year-old to stop playing video games and to join me for a few minutes of catch outside. He reluctantly agrees, and proceeds by asking Alexa to turn off his TV on his behalf.
Oh well. At least it’s a start.
is an associate professor of medicine and senior scientist at the Toronto Rehabilitation Institute at the University of Toronto. This article was originally published on The Conversation.