By JIM GERARD
For years, the consensus was that an hour a day of exercise, three to five times a week—or any of its many permutations, would keep one fit.
However, a growing body of evidence suggests that what people do when they’re not exercising determines their true level of fitness. This has led to a phenomenon that Nancy Clark, director of nutrition services at SportsMedicine Associates in Brookline, Mass., calls the “sedentary athlete.”
According to Dr. Neville Owen, a speaker at the American College of Sports Medicine’s 2009 Annual Meeting, the average person sits 9.3 hours a day. The Nielsen company reports that the average American watches five hours of television during that same day, while other studies show that most Americans spend another hour Internet surfing. Add to that all the e-mailing, texting and Tweeting, and stack it up against a four-day-a-week step class—which is what a rash of new studies are doing—and the news isn’t good.
Warning: Prolonged Sitting May Cause “Detrimental Metabolic Effects”
New research implies that even if people are physically fit, long, uninterrupted periods of sedentary behavior are bad for their health. This extended sloth can cause what scientists call “detrimental metabolic effects.” That is, it may mitigate, if not erase, the benefits of exercise and lead to a state labeled “couch potato fitness.”
Australian researchers led by Dr. Geraldine Healy, research fellow at the Heart and Diabetes Institute at the University of Queensland, determined that longer average bouts of sitting and lying down (independent of the total per diem veg-out time) are associated with a higher percentage of body fat, in women—although, curiously, not men. In the researchers’ words, “These findings provide preliminary evidence on the potential importance for human health of avoiding prolonged periods of being sedentary, independent of physical activity. [They] support findings from studies of the metabolic consequences of television viewing time.”
Additional studies conducted by Healy’s team, Dr. David Levine and his fellow Mayo Clinic researchers, plus others, all come to the same conclusion, regardless of gender. Low levels of non-exercise activity thermogenesis (what Levine calls “NEAT”), or how much energy is burned from all physical activities “other than volitional sporting-like exercise” such as playing with kids, manual labor and dancing—are the source of America’s obesity epidemic.
Other studies by Healy have shown that high TV watching and sitting time greatly corresponds to metabolic syndrome, the cocktail of disorders—including larger waist sizes, and increased triglyceride and blood glucose levels—that increase the risk of developing cardiovascular disease and diabetes. And a 2010 study revealed that high TV time—independent of exercise—was associated with a higher risk of premature cardiovascular disease mortality. In other words, no matter how hard someone may work out, too much channel surfing can shorten his or her life.
Other Experts Weigh In
Not all the experts have signed off on the veracity of these studies. Dr. David Nieman, a professor of health and exercise science at Appalachian State University in Kannapolis, N.C., says, “[Healy’s] studies are interesting, but it’s going to take a lot more evidence to be convincing. I feel ultimately they will be discredited due to their small sample size.” (The latest Australian study used only about 100 subjects.)
Dr. Kent Holtorf, medical director of the Holtorf Medical Group in Los Angeles, ripostes, “There is no perfect study. Evidence-based medicine is taking what the evidence is currently for that issue. To say this or that study isn’t long enough is a cop out.”
The weight of evidence seems to lie with NEAT. Certainly, Western society makes it far too easy to do nothing. As Levine puts it, we live in “a chair-enticing environment.” He claims that many people who have an innate tendency to sit in one position—as opposed to fidgeting—for long periods of time become obese.
The immediate ramification of this science for the fitness community is that it forces us to rethink the CDC’s 2008 exercise guidelines—that 150-minutes, 10-minutes-at-a-time of cardio plus two hours of strength training per week will keep you fit.
The CDC doesn’t delineate how to spend the time away from the gym. That may be because the researchers haven’t studied it. Holtorf says, “It’s hard to determine because some people might be foot-tappers or pacers, while others—even those regular gym-goers—might tend to do a lot of stationary sitting.” And sitting is not something for which humans are built, evolutionarily speaking.
“As recently as 50 years ago, people were moving all day long,” says Nicki Anderson, IDEA 2008 Fitness Trainer of the Year. “They mowed their lawns, [manually] opened their garage doors and hung their laundry out to dry. The musculoskeletal system constantly was being used. Sitting all day weakens your joints, decreases metabolic rate and perpetuates fatigue and poor posture, often contributing to back pain.”
And objectively speaking, says Holtorf, it may not matter how much or intensely we exercise. “It’s what the body perceives us as doing, and the body is historically more used to constant motion. Besides, the average person on the Stairmaster doesn’t really burn that many calories in an hour.” Healy lays out the lamentable facts: “Even lean individuals store at least two to three months of their energy needs in adipose tissue, whereas obese persons can carry a year’s worth of their energy needs. Obesity is the cumulative impact of energy imbalance over months and years.”
Further complicating the picture, adds Holtorf, is the fact that our “catabolic mode”—or the rate at which we burn calories—depends on many factors, including our previous fitness level, genetics, even our previous dieting history. “One study showed that people who have dieted and lost weight had a 25 percent lower metabolic rate than others of the same age, body fat and weight. Other studies have revealed that women who over-exercise and diet also have a [s]lower metabolism. Dieting and overtraining can shift the body into starvation mode.”
He adds, “To attain metabolic equilibrium, an individual must want to hit that sweet spot.”
Taking a Whole-day Approach to Physical Activity
Healey believes the key to attaining that state is to take a “whole day” approach to physical activity and try to incorporate movement across the day, not just when you hit the running track or bike trail.
“Since incidental movements make up the bulk of energy expenditure for the average person, every little bit helps. Office workers can stand while on the phone, walk to see a colleague down the hall and take the stairs instead of the elevator.” She also suggests incorporating less-expensive technologies such as using height-adjustable desks and moving bins and printers to central locations.
It is important, Holtorf argues, to develop a consistent routine. “In your 15-minute work break, do intensive exercise using a pull-up bar or light weights. This is better than taking a ‘brisk’ walk, which the body may not perceive as physiological stress.” Other ideas: Pace while making phone calls and stand up when re-decorating Facebook walls.
One source suggested introducing walking treadmills for office workers, but that may be both logistically risky and financially prohibitory to accomplish on a large scale. But stability ball chairs are doable. Plus, people can bike to work, cities can build more greenways, politicians can recommend closing off downtown areas to traffic (as Mayor Bloomberg has in New York City), and, of course, educators can put physical education back into the school curriculum. “Exercise has been engineered out of our lives,” explains Levine, “and we have to re-engineer our work, school and home environments to render active living the option of choice.”
Helping Clients Get the Right Message
Fitness professionals must find ways to convey these results and their ramifications to even their most dedicated clients. “I typically tell my clients that intentional exercise—going to a gym or out for a run—is not nearly as important as unintentional exercise, keeping their bodies moving throughout the day,” says Anderson. “If they’re stuck at a desk, they should make an effort to get up and walk around the office at least once per hour.” Anderson also recommends that her clients “sneak in” exercises during conference calls or while doing paperwork, using portable exercise bands and tubes that can be attached to a desk or doorframe. For more ways to exercise at your desk see the ACE Fit Fact, "Time-saving Tips for On-the Job-Fitness."
How do we know how much ancillary movement we need on a daily basis? Holtorf says this is a tough question. Along with the prior suggestions, he advises using a pedometer and counting the number of steps we take each day. Most experts recommend accumulating 10,000 or more steps per day.
Suffice it to say that the manner in which we add movement and activity to our mundane tasks is less important than the quantity. The bottom line, says Clark, is that it’s “not healthy for a person to exercise one hour a day and sit the rest of the time.”
For additional information on NEAT, please see the July 2010 Health eTips article Burn More Calories on the Job.
Jim Gerard is an author, journalist, playwright, and stand-up comic. He has written for the New Republic, Travel & Leisure, Maxim, Cosmopolitan, Washington Post, Salon, Details, New York Observer, and many other magazines. For more information, visit his site at www.gangof60.com