Hot Seat: Warding off Sitting Disease
Posted On Sep 13, 2016
by Karen Asp
In your quest to live healthier, you’ve switched to natural cleaners, kicked up consumption of fresh, organic produce, and joined a gym. While these are great moves, one change could be a lifesaver. Stop slumping in that chair and stand tall.
A SITTING DISEASE
People sit between eight and 10 hours a day—50 to 60 percent of waking hours—says Genevieve Healy, Ph.D., a senior research fellow at the University of Queensland in Australia. It sounds odd, as sitting is a part of everyday life, but the time has come to rethink your chair.
Why? Humans were designed to move. It took a long time for sitting to become an activity shared by the masses. Centuries ago, sitting was largely reserved for the privileged. Today’s world is designed for sitting, and we’re faced with the stark realities of what’s known as “sitting disease.” “From garage door openers to remote controls, we’ve engineered movement out of our lifestyle in a drive towards efficiency,” says Peter Katzmarzyk, Ph.D., associate executive director for population and public health sciences at Pennington Biomedical Research Center in Baton Rouge, Louisiana. That efficiency could cost you your life: “The more time spent sitting, the greater the risk of dying,” Dr. Katzmarzyk says. Some experts have even dubbed sitting, the new smoking.
The potential for premature death is the takeaway from a study in the American Journal of Epidemiology. The study, conducted over 13 years, shows that women who sat more than six hours a day, regardless of exercise, were 37 percent more likely to die of myriad causes (including heart disease and cancer) than women who sat less than three hours a day. Men who logged the same sitting time were 18 percent more likely to die from a plethora of causes.
Lots of sitting, combined with low physical activity, increases those numbers to 94 percent in women and 48 percent in men. Prolonged sitting appears to have big metabolic consequences. It influences variables like cholesterol, triglycerides, resting blood pressure, fasting plasma glucose, and leptin. These are biomarkers of chronic conditions such as cardio-vascular disease.
Excess sitting has also been linked to type 2 diabetes, depression, cancer, and obesity. A study in the journal Obesity found that the 25 percent of people who take minimal sitting breaks during the day have a two and a half-centimeter larger waist circumference on average than the 25 percent of people who took the most breaks. “Even if you do 30 or 60 minutes of exercise but sit the majority of the day, that’s bad for your health,” says Healy, one of the authors of the study.
How does standing slim a waist? “You’re engaging the large postural muscles in your legs and back, resulting in increased muscle contraction activity and associated uptake of blood fats and blood sugars,” says Healy. Add movement to those breaks, and you use more energy, which impacts energy balance and therefore your waistline.
HOW MUCH IS TOO MUCH
As research about sitting’s detrimental effects continues to mount, questions loom. The biggest one: How much sitting is too much?
Researchers can’t say for sure. One of Katzmarzyk’s studies found that reducing sitting time to less than three hours a day could increase life expectancy of Americans by two years. (The current life expectancy for men is 76.4 years, women 81.2 years). That’s not yet enough to make definitive recommendations, but researchers know this: “The relationship between sitting and health consequences is linear, Katzmarzyk says. “More sitting is clearly bad.”
They also know that sitting less doesn’t give you a pass from the gym. For optimal health benefits, you still need to log recommended
amounts of physical activity (150 minutes of moderate- intensity or 75 minutes of high-intensity aerobic activity, as well as two or more strength-training activities a week). “There are gains to be made in the gym that can’t be replicated through light-intensity movements,” notes Healy. If you’re not sitting, you’re either standing or moving, hence the proliferation of treadmill desks, desk cycles, and stand-up desks, but these also create problems.
Walking and cycling at the office can decrease computer work performance, slowing typing and increasing mistakes. Standing while working, on the other hand, can cause other issues. “It’s more tiring than sitting, using 20 percent more energy,” says Alan Hedge, Ph.D., director of the human factors and ergonomics laboratory at Cornell University in Ithaca, New York. It also increases risk of varicose veins and places strain on the circulatory system in the legs, feet, and back, which can increase low-back discomfort and negatively impact men in particular with heart disease.
DANGERS OF SITTING TOO LONG
All of this leaves you in an interesting position, given that you’re neither supposed to sit nor stand too much. So what’s a health-seeking soul to do? Simply put, take more butt breaks, preferably every hour—if not sooner.
A study in Medicine & Science in Sports & Exercise has found that walking just five minutes every hour in the midst of three hours of sitting actually prevents some of the harmful effects of sitting. Healy, meanwhile, suggests that you stand at least every 30 minutes—a recommendation Australia has added to its national physical activity guidelines.
It’s not just about standing more often, but changing your posture when you do stand, which is why walking is so beneficial. “The best posture is the next posture, so change positions frequently,” says Healy, who adds that most ill effects from excess standing have occurred in occupations that entail long periods of standing without regular changes in posture.
Hedge recommends no more than 20 minutes of sitting, followed by a minute of standing and two minutes of moving and stretching. Repeat this throughout the day. If you want to stand more while working, do it for short periods. Avoid leaning and awkward positions.
Researchers hope that environmental and cultural changes will begin to occur within public places to make standing and moving around more acceptable. Until that time comes, though, view the chair at your work desk with a bit more skepticism. Your life really may depend on it.