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 exercise session, if it’s actually performed—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 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.
The weight of evidence seems to lie with NEAT. Certainly, Western society makes it far too easy to do nothing. Some studies suggest 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 established exercise guidelines—that 150-minutes, 10-minutes-at-a-time of cardio plus two hours of strength training per week will keep you fit.
“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 was constantly being used. Sitting all day weakens your joints, decreases metabolic rate and perpetuates fatigue and poor posture, often contributing to back pain.”
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. Every little bit of movement 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.” 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.
Plus, people can bike to work, cities can build more greenways, politicians can recommend closing off areas to traffic to promote walking and cycling paths 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.”
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.”
Richard Geres is an ACE-certified Personal Trainer
www.richardgeres.com