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January 7, 2016

Study will evaluate value of reducing sit time, inactivity


Researcher Bethany Barone Gibbs works at her adjustable sit-stand workstation.

The aphorism “Sitting is the new smoking” is now commonplace when it comes to describing the negative health effects of inactivity.

Sitting for prolonged periods allows blood to pool in the legs, resulting in a higher resting blood pressure. And, sedentary living — including hours of sitting at work — is linked with increased risk of cardiovascular disease, diabetes, some cancers and premature death.

Even if a person exercises for the recommended 30 minutes a day, “That’s only about 3 percent of your waking hours, leaving 97 percent of your time as sedentary or doing light activity,” said epidemiologist Bethany Barone Gibbs, a researcher in the School of Education’s Department of Health and Physical Activity who is studying the use of sit-stand desks.

Labor-saving conveniences that made life easier for our hardworking ancestors have continued to advance, pushing even light activity levels lower. With dishwashers, computers and online shopping, “We’re engineering light activity out of our lives,” Gibbs said.

“Humans weren’t designed to sit all day,” she said. “Our bodies were made to move.”

Graduate student Anna Peluso demonstrates an improvised sit-stand workstation created by using a two-tiered stool to bring the computer and keyboard up to the appropriate height for someone who is standing.

Graduate student Anna Peluso demonstrates an improvised sit-stand workstation created by using a two-tiered stool to bring the computer and keyboard up to the appropriate height for someone who is standing.

An international team of experts recently published guidelines in the British Journal of Sports Medicine that recommend that office workers aim for two-four hours of standing and light activity during the workday.

Observational studies have found that people who have less light activity and more sitting tend to die sooner, weigh more and have more cardiovascular disease and diabetes, but how much activity is needed to reduce the risk? Gibbs is working to find out.

“There’s no evidence that changing the behavior will work,” she said. “We don’t know anything about the dose yet.”

And while it may make sense that moving more is better, standing all day isn’t good, as other research involving machine operators and production workers attests, she said.

Is there a sweet spot? And where might that be? Studying people who shift to a sit-stand workstation provides a way to find out. “We’re in the space in the research where we need to see how to make people change the behavior so we can see if the change makes a difference.”

Gibbs’ earlier research has found that simply having a sit-stand desk boosted the amount of time research subjects spent standing. She uses an adjustable sit-stand workstation herself. Her dose is unscientific: “I stand as much as I can. If I’m tired, I sit down.”

Alternating sitting and standing over the course of an eight-hour work day can burn an extra 40-50 calories a day, helping to stave off weight gain, she said.

In addition to burning extra calories, activity, particularly after a meal, aids glucose metabolism. In research subjects who were given the same meal, followed by either standing or sitting, blood sugar peaked less for those who stood, she said. “It was a small effect, but if it’s every day, the cumulative effect is big.”

Compared with people who sat after eating, those who stood “felt more energy, less tired and perceived greater productivity,” she said.

“Eat, then ideally take a 3-5 minute walk,” she recommended. “Then stand for a half-hour, then sit for a half-hour.”

A 3-5 minute walk could be as simple as choosing to use a restroom two floors away, or walking to a printer farther away than the one you ordinarily would use, she said.

“Efficient people group their errands together, but that’s how we got into this bad fix of sitting all day,” Gibbs said, recommending that people spread out their office tasks to add walks to their day.

“It seems inefficient but if you make it a priority and build it into your day it will become a habit.”

Now trendy, “active office” furniture can be expensive, with some desks costing well upward of $1,000, but there are alternatives to purchasing a sit-stand workstation, she said: Use a hospital-style bedside tray stand, raise your computer and keyboard with a stepstool, or use the high countertop at a reception desk for some tasks, Gibbs suggested.

Gibbs, in conjunction with Andrea Hergenroeder of the School of Health and Rehabilitation Sciences, is turning her attention to chronic low-back pain, a debilitating condition that’s both expensive to treat and the cause of many lost work days.

Gibbs is recruiting 30 participants with chronic low-back pain and sedentary desk jobs for a six-month study to determine whether a sit-stand workstation and periodic activity during the workday will decrease pain and increase function.

Sitting at a desk hasn’t been found to cause low-back pain, “but for people who have low-back pain, sitting all day will make it worse,” said Gibbs.

Half of the study participants will use a sit-stand workstation and an activity prompter wristband. All will receive monthly online questionnaires with questions about medication use, doctor visits and work absenteeism, she said.

“We hypothesize it will be better for people who have the (sit-stand) desks,” she said.

Participants don’t get to keep the workstations, but all will get a Jawbone UP band. For information on the study, call 412/383-4035.

—Kimberly K. Barlow   

Filed under: Feature,Volume 48 Issue 9

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