Researcher helps define internationally used terms about sedentary behavior
Friday, Aug. 4, 2017
MANHATTAN — A large body of research shows that being sedentary has negative effects on health, but until now, there was no international consensus on what sedentary really means.
Because of this, various studies on sedentary behavior have essentially compared apples to oranges, says Sara Rosenkranz, assistant professor of food, nutrition, dietetics and health at Kansas State University.
Rosenkranz has collaborated with an international team that developed consensus on several definitions regarding sedentariness, including stationary behavior versus sedentary behavior, reclining versus lying, and other terminology.
Rosenkranz co-authored the paper "Sedentary Behaviour Research Network: Terminology Consensus Project Process and Outcome" in the International Journal of Behavioral Nutrition and Physical Activity in June. The study, which has been translated into nine languages, was written with 83 other members of the Sedentary Behaviour Research Network who were from 20 countries.
"I am grateful for the opportunity to participate in such a huge collaborative effort on a great international team, and I appreciate how careful and thorough the leaders were in administering the consensus process," Rosenkranz said. "It was exciting to see such an extensive project come to fruition and get published in a top-notch journal."
Researchers from the Children's Hospital of Eastern Ontario Research Institute developed a list of terms with conflicting uses that were published in literature related to sedentary behavior, Rosenkranz said. The researchers sent this list to a steering committee of Sedentary Behaviour Research Network members, who reviewed and modified the list. Next, they invited all network members to review the list, provide feedback and draft definitions through an online survey. Finally, the research institute used the network members' feedback to finalize the definitions, as well as caveats and examples for varying age groups and functional abilities.
Rosenkranz contributed to several topics in the paper, including the need to clarify whether standing included light physical activity such as shifting weight from one foot to the other, and whether sitting included movement such as fidgeting. Because of contributions from Rosenkranz and other participants, the paper distinguishes between active and passive forms of sitting and standing.
The team arrived at consensus for 10 definitions and grouped behaviors into three categories: sedentary time, physical activity time and sleeping time. Unlike many previous definitions, the newly approved definitions apply to a broad spectrum of populations, including young children and people with disabilities, Rosenkranz said.
Rosenkranz became aware of the need for consistent definitions while conducting a study on sedentary behavior as a doctoral researcher at Kansas State University in 2010. When writing a grant for the study, which defined sedentariness as prolonged sitting, she found that some people used the term sedentary to mean someone who was not getting the recommended amounts of moderate to vigorous physical activity.
Under the approved definitions, the term for that behavior would be physical inactivity, which could be found in a person who has very little sedentariness but has only light physical activity. In contrast, sedentary behavior is defined as any waking behavior characterized by an energy expenditure less than or equal to 1.5 metabolic equivalents while in a sitting, reclining or lying posture. A person could have extensive sedentary behavior but not be physically inactive because they exercise for half an hour before sitting the rest of the day, Rosenkranz said.
"Having these consistent definitions will help move sedentary behavior research forward," she said. "This is a research topic that has exploded in the past decade and will continue to be an important area of study."
Rosenkranz thinks the peer review process naturally will enforce the approved definitions because papers that are submitted for publication will be edited by sedentary behavior reviewers who likely will be aware of the approved definitions and hold newer scientists accountable to the definitions.
"It's important that everyone in the field, whether they are exercise physiologists or behavioral researchers, is on the same page, speaking the same language and talking about the same thing," she said.
The food, nutrition, dietetics and health department is part of the College of Human Ecology.