- Studies have linked sedentary behavior to increased risk for heart disease, diabetes and cancer.
- Daily exercise may not be enough to compensate for hours of sitting.
- Some experts say changing workplace behavior and design can encourage worker movement throughout the day.
By Ashley Johnson, associate editor
Desk jobs might be considered safe by the general public, but a growing body of research suggests that all that time spent sitting – in front of a computer, in meetings, even driving to and from work – may be harmful to your health. Studies have linked long periods of sedentary behavior, primarily sitting, to increased risk of obesity, diabetes, cardiovascular disease and cancer. Simply exercising on your lunch break or after work may not be enough to undo the damage.
Instead, researchers such as endocrinologist Dr. James Levine recommend more movement throughout the day. Given how much time people spend at work, the workplace has emerged as a prime target for interventions to reduce sedentary time.
Levine, professor of medicine at the Rochester, MN-based Mayo Clinic, has taken what some people consider a radical approach: He developed a treadmill workstation that allows people to walk at a comfortable pace while working. Most people who use the machine spend a couple hours per day on it. That may not sound like much, but, “Two and a half hours of walking which would have been sitting is an astronomical difference,” Levine said.
Harmful effects of inactivity
Levine spoke of the NEAT revolution, a concept he coined that stands for “non-exercise activity thermogenesis” and represents the calorie expenditure of daily living outside of structured exercise. As Levine put it, “Everything that isn’t sleeping and eating is NEAT.”
He recommends increasing NEAT for two reasons – one, weight management can have associated health benefits; and two, moving more throughout the day helps reduce sitting time. “The global impact of prolonged sitting may be very great indeed. Time will tell,” Levine said.
Emerging research points that way. A study published in the May 2010 issue of Medicine & Science in Sports & Exercise (Vol. 42, No. 5) found that men who reported more than 23 hours a week of sedentary behavior had a 64 percent greater risk of dying from cardiovascular disease than men who were sedentary for less than 11 hours a week.
Heart concerns are not new. In 1953, The Lancet (Vol. 262, No. 6796) published British research that showed cardiovascular disease was less frequent and less severe among bus conductors and postmen than bus drivers and telephone operators, who are more sedentary.
More recently, an Australian study published in Diabetes Care in April 2008 (Vol. 31, No. 4) linked breaking up sedentary time with movement to a healthier waist circumference, body mass index and triglyceride count.
“Now we’re starting to understand that reincorporating some physical activity and being less mechanized is actually a good thing,” said Christine Friedenreich, adjunct professor of medicine and kinesiology at the University of Calgary in Alberta.
Friedenreich’s research review indicates a connection between long bouts of inactivity and biomarkers for cancer. She explained that people who are more sedentary are more likely to accumulate body fat, which has an effect on insulin resistance and inflammation, as well as certain hormones tied to breast cancer.
Friedenreich stressed that the standard guideline of 150 minutes per week of moderate-intensity physical activity is not enough to counteract the effects of moderate sitting.
Likewise, Marc Hamilton, professor at the Pennington Biomedical Research Center in Baton Rouge, LA, warned against conflating reduced sitting with weight loss; too much sedentary behavior is a problem regardless of a person’s weight. His research on “inactivity physiology” indicates that the cellular processes triggered by excessive sitting are different from the body’s response to exercise.
Hamilton cited figures that show sedentary time takes up more than 9 hours – roughly 60 percent – of the average person’s waking hours. For him, the question is how to significantly reduce that sitting time.
Walking over to a co-worker instead of sending an email may give a person a chance to stretch, but he called those extra minutes of activity a “drop in the bucket” in the context of how much time people spend sitting. “In the workplace, the solution is not obvious and it’s not easy,” Hamilton said.
Activity in the workplace
Levine has a different perspective, which could be summed up as “every little bit helps.” Friedenreich recalled attending a seminar during which Levine gave his lecture while walking around the room, between tables, rather than standing at a podium.
Cutting sitting time fits with the increased emphasis on wellness in many workplaces. In addition to architectural redesign – such as the treadmill desk – Levine described simple behavioral modifications, including walking meetings and conducting phone conversations standing up instead of sitting down.
The old recommendation to get up every hour and walk for 10 minutes still stands, although Levine said people need to take the cognitive step of making the movement a deliberate action.
Some employers have created walking tracks using tape on the carpet. Levine said this idea is “very powerful because it is a visual reminder pretty much all the time that walking is encouraged in this office.”
Another idea is to decorate staircases with photographs of workers and their families or pets so that people will then take the stairs to see the images.
The benefits of physical activity interventions may extend beyond individual employees. Levine said data from employers he has worked with shows a positive return on investment. “We have never conducted a program where productivity has declined,” he added.
Dr. Antronette Yancey, a professor in the Department of Health Services at the University of California at Los Angeles, promotes breaking up inactivity with regular 10-minute group exercise breaks.
Yancey calls the concept “instant recess,” which is also the name of her book. The idea is that workers stop what they are doing and gather in a central place to perform a low-impact, structured physical activity.
At Kaiser Permanente’s South Bay Health Center in Harbor City, CA, regular exercise breaks have led to a decrease in injuries, increased morale and employee engagement, and decreased absenteeism, Yancey said.
Her focus is not weight loss, but rather promoting health and well-being. As for why people neglect physical activity, Yancey said, “It’s not really a knowledge gap. It’s a motivation gap. It’s a perception of what priorities are in people’s lives.”
Success in the workplace requires a change in culture as well as activity levels. “What many people fail to realize is that the basic activity level of the average American adult is extremely low,” Yancey said. “We’re trying to make activity the default option.”