August 13, 2013
How many hours per day do you spend sitting in a chair? If you’re like many Americans, it’s probably somewhere between eight and ten. From driving to work, sitting at a desk all day and coming home to watch television on the couch, we’ve virtually engineered physical activity out of our daily routines.
But our bodies did not evolve to be sedentary.
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“Biologically, it makes great sense that we’re set up to be most productive and happiest when we’re physically active. We’re literally designed to do that,” says Michael Birt, director of Sustainable Health at Arizona State University’s Biodesign Institute. He doesn’t just talk the talk. He also walks the walk – every chance he gets.
From installing standing desks in the office to organizing walking meetings with colleagues, Birt refuses to sit still. And he’s in good company – many others at ASU and all over the world are heeding the advice of health experts who insist that we’re falling victim to an unlikely killer: the chair.
When you sit, electrical activity in your muscles stops. Your body’s calorie-burning rate slows substantially. The enzymes responsible for breaking down fat in your bloodstream plunge, causing levels of good cholesterol to drop as well. Imagine your body being in this state for eight hours a day for the majority of your life. It’s no wonder scientists have made a connection between the sedentary lifestyle and America’s obesity epidemic.
Sitting ourselves sick
James Levine is co-director of the Mayo Clinic/ASU Obesity Solutions Initiative and an international expert on obesity. He is known for developing the treadmill desk, which allows a user to walk in place at a comfortable pace as they work. He’s also known for ominous warnings that sitting is “a lethal activity.”
Research backs him up. Studies have linked prolonged sitting with health risks such as obesity, high blood pressure, high blood sugar and abnormal cholesterol levels. Levine led one study that found adults who spend more than four hours per day in front of the television have a 50 percent increased risk of death and a 125 percent increased risk of suffering from cardiovascular disease, compared with adults who spend less than two hours per day sitting in front of the tube.
But what about those of us loyal gym members? Will a daily run counteract the effects of being sedentary? Not necessarily. Levine’s research shows that people who stand, fidget and move around throughout the day are healthier than those who spend the majority of their time sitting, even if the sedentary folks carve out a section of their day for some concentrated, intense activity.
“The idea is that going to work out at the gym for 60 minutes and then coming to an office and sitting for eight, nine, 10 hours – that sitting undoes almost every bit of good you do at the gym,” Birt says. He and others at ASU are finding innovative ways of empowering people to take control of their health with new technology.
Breathing out biomarkers
In fact, Birt and his colleagues at Sustainable Health were the “human subject guinea pigs” for a new device called Breezing, the world’s first portable metabolism tracker. Breezing was created with technology developed at ASU by a team led by Nongjian (NJ) Tao, director of the Center for Bioelectronics and Biosensors at the Biodesign Institute.
Breezing tracks an individual’s metabolism over time and creates a personalized diet and exercise plan. The core of the technology is an interactive sensor, which measures oxygen consumed and carbon dioxide produced. These gases serve as biomarkers – substances in the body that provide information about a person’s health status.
“When I breathe into this little mouthpiece, my breath goes into Breezing and interacts with the sensor cartridge, generating an optical signal, which is converted into an electronic signal. Then it gets processed and transmitted through Bluetooth to my cellphone,” Tao explains.
Breezing detects and records a user’s metabolism, his or her respiratory quotient (whether the body is burning carbs, fats or a mix of both) and weight history over time. It’s all collected by a small, portable device and downloaded instantly and wirelessly to the user’s cellphone.
“Now, everybody has a cellphone and people use it not just to make phone calls, but to check email, read the news, use GPS location and so on. It’s not just a communication tool, but also brings information access. With that in mind, we think cell phone-based personal health devices really are the future,” Tao says. And others at ASU agree.
Wearing your health on your sleeve
Matthew Buman, a professor in the School of Nutrition and Health Promotion, is also exploring new technological ways of getting people to take charge of their health. One of his projects involves building smartphone apps that encourage mostly sedentary people to stand up more often.
Another area of interest is the field of wearables – personal, wearable health devices that measure things like physical activity, heart rate and sleep.
One such device is the Jawbone UP band, a wrist-worn pedometer that connects to the headphone jack of a cellphone. When connected, the device syncs with an app that downloads and displays data collected by the UP band. This includes the number of steps you’ve taken in a given day and the amount and quality of sleep you had the night before. The smartphone app also allows users to record their mood and diet. They can post their data to social media accounts and form teams with their friends to keep each other motivated.
Birt wears an UP band himself and appreciates the social aspect of the technology.
“My daughter is on my team. She sends me texts all the time saying things like, ‘Way to go!’ or ‘Gee, you didn’t sleep so well last night!’” Birt says.
Others within Sustainable Health wear FitBits, which attach to a belt loop and also collect data on physical activity that can be synced to social media. Not surprisingly, obesity expert Levine served as a scientific advisor to the creators of FitBit.
The 24-hour health cycle
Buman is currently conducting a validation study of the UP band to see if it’s as accurate as research-grade devices that are more expensive and less appealing to wear, compared to the UP band’s sleek and stylish design. He says an important function of the band and other wearables is their ability to obtain data continuously, giving users a full 24-hour picture of their health.
“We’ve known for a long time that what you eat and your activity during the day makes a big difference, but we’ve mostly ignored the fact that we sleep for a third of our life,” Buman says.
As it turns out, sleep and physical activity are closely connected. When someone doesn’t get enough sleep, it changes his or her biology in a big way. A lack of sleep can throw off the release of the right hormones at the right times across our circadian clocks, or as Buman says, “the clock that keeps us ticking, so to speak.”
For example, several studies have shown that restricting sleep causes the body to produce a hormone called leptin, which can promote hunger.
“Suddenly, you haven’t slept as much and you’re more likely to consume greater amounts of food,” Buman says. But this cyclical pattern can be reversed. If you get a good night’s sleep and feel energized enough to be physically active the next day, that exercise will pay off in better quality sleep that night.
Whether or not personal health devices like Breezing or the UP band will reverse the obesity epidemic remains to be seen. But as an expert in health behavior change, Buman says personalized feedback and social support are extremely important, whether people are trying to change their diets, be more physically active, quit smoking or even improve their sleep.
“There is a lot of opportunity to harness social connectedness and social support that wasn’t necessarily there before,” Buman says. “We’re moving toward more personalized ways to lead a healthy lifestyle.”
And personalized sensing technology based on biomarkers offers huge potential. For example, Tao has used Breezing as a model to develop another device that measures nitric oxide, a biomarker of asthma. Other biomarkers can provide early detection of diseases and conditions, leading to improved prevention and diagnosis.
“Ten or 20 years from now, the ability to capture this data will be as simple as maybe a little tag or a little Band-Aid on your wrist that will provide so much more data and be able to analyze it and then connect with your health care provider,” Birt says. “I think we’re just at the Stone Age for these tests and devices.”