Eight hours of work each day, eight hours of sleep each night, and a jumble of carpooling, errand-running, cooking, cleaning, home repair, and sitting (if you’re lucky) all but exhausts the 24 hours we’re allotted each day. A new study shows this busy schedule leaves out the important factor of exercise, as obese women receive an average of only one hour of exercise over the course of a year.

The U.S. Department of Health and Human Services recommends the average person engage in 150 minutes of moderate aerobic activity, or 75 minutes of vigorous activity, each week. Generally speaking, that’s 30 minutes of physical activity each day. But as researchers from the University of South Carolina Arnold School of Public Health have found, a day’s worth of exercise for obese women takes, on average, six months to complete.

There used to be a time when people didn’t have to go to a specific building and pay a monthly fee just to stay in shape; manual labor and self-sufficient diets kept us healthy by default. But as we got better at building things to do the work for us, we created more jobs that required us to service those tools. Instead of assembling products by hand, we create machines to do it for us; meanwhile, we man the control desk and make sure each part runs smoothly. Instead of traveling on foot in the search for knowledge, we invented the Internet. So now we sit at desks, trading ideas as our currency rather than skills.

What all this technological evolution really amounts to is a group of people that’s forgotten what it means to move. Sitting is the default. We lie down while we sleep. We sit in cars on the way to work. We sit at the office. We sit in front of the TV. Rinse and repeat. Fortunately, science has kept up with these trends, which means we can learn how dangerous sitting is for our health — even while we do it.

"They're living their lives from one chair to another," Edward Archer, a research fellow with the Nutrition Obesity Research Center at the University of Alabama at Birmingham, told HealthDay. "We didn't realize we were that sedentary. There are some people who are vigorously active, but it's offset by the huge number of individuals who are inactive."

Archer and his colleagues tracked the weight, diet, and sleep patterns of nearly 2,600 adults, aged 20 to 74, between 2005 and 2006. Alongside the expected differences between men and women (such as men being taller and heavier) were more surprising findings, namely, that men received just under four hours of exercise (3.6 hours) per year compared to women’s one. Subjects wore accelerometers so that the research team could rely on hard data rather than self-reports, which are notoriously untrustworthy. Sexual activity wasn’t included.

Exercise was defined as “vigorous” activity that burns fat, such as jump-roping or jogging — a definition pegged by some critics as too restricting. The data unhelpfully leaves out, for example, the myriad obese people for whom “vigorous” exercise isn’t in their best interest, and who would safely benefit from walking or other low-impact exercises like yoga or swimming.

"People don't understand that [you] don't have to go to the gym and lift weights and run marathons to have dramatic impacts on your body,” Archer sympathized. “Standing rather than sitting, walking rather than taking your car, they have huge impacts on your health over time."

The benefits of physical activity don’t just apply to singular workout sessions either. When you exercise your brain releases feel-good hormones known as endorphins, and it’s these chemicals that enhance your mood for hours after you work out. They’re produce the infamous “runner’s high.” And even though you may never reach an intensity level where running makes you feel euphoric, University of Pittsburgh health and physical activity department chair, John Jakicic, said low barriers to entry are hugely motivational.

“We showed a number of years ago that encouraging multiple brief periods — five to 10 minutes two to three times per day — was an effective way to get individuals active initially,” he told HealthDay. “Once they started to become more active in this way, they started to add even more activity."


Source: Archer E, Hand G, Hebert J, et al. Validation of a Novel Protocol for Calculating Estimated Energy Requirements and Average Daily Physical Activity Ratio for the US Population: 2005-2006. Mayo Clinic Proceedings. 2014.