Active Voice: Sedentary Behavior in Old Age is Rooted in Midlife — Intervene Early! By Julianne van der Berg, M.Sc., and Annemarie Koster, Ph.D. Annemarie Koster, Ph.D. Julianne van der Berg, M.Sc Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM. Julianne D. van der Berg, M.Sc., studied health sciences at VU University Amsterdam, The Netherlands. After graduation, she joined the Exercise, Nutrition and Health Sciences department at the University of Bristol (UK), where she worked on projects focusing on physical activity, physical environment and health. Since 2012, she has been working at the Maastricht University as a Ph.D. candidate, investigating effects of leading a sedentary lifestyle on type 2 diabetes and its complications. Annemarie Koster, Ph.D., is an assistant professor in the Department of Social Medicine at Maastricht University in the Netherlands. As an epidemiologist, her research focus centers on understanding the causes and consequences of physical (in)activity and obesity in old age. She has a strong background in physical activity assessment by accelerometry, with a particular interest in the health effects of sedentary behavior. This commentary presents Ms. van der Berg’s and Dr. Koster’s views on the topic of a research article which they and their colleagues had published in the July 2014 issue of Medicine & Science in Sports & Exercise® (MSSE). In 2011, ACSM published an online brochure titled “Reducing Sedentary Behaviors: Sitting Less and Moving More” that reported on the harmful effects of too much sitting. Sitting or other sedentary behaviors such as lying down, watching TV and using the computer have been studied extensively during the last several years. Studies suggest that even when you exercise regularly, prolonged periods of sedentary time are a risk factor for cardiovascular disease, type 2 diabetes and even mortality. What is not well-understood yet is what factors influence the amount of sedentary time. Our recent article in MSSE reports on an investigation where we examined factors present in midlife adulthood that were associated with subsequent sedentary behavior in old age. We used data of 565 adults participating in the Age, Gene/Environment Susceptibility (AGES)-Reykjavik Study in Iceland. Measurements were obtained in all participants during midlife at the average age of 49 years and, again, in old age (average age of 80 years). During midlife, we measured factors in four domains: demographic factors (e.g., sex, age, marital status); socioeconomic factors (e.g., level of education, housing type, occupation); lifestyle (e.g., smoking status, physical activity, active commuting, occupation activity); biomedical factors (e.g., body mass index (BMI), weight status, blood cholesterol levels, heart disease, type 2 diabetes). Approximately 30 years later, we objectively measured the time people were sedentary over multiple days, using an accelerometer. We examined which of the factors measured during midlife were associated with sedentary time in old age, independent of the participants’ current health status and level of physical activity. Our results showed that lower educational level, poorer housing and not being married were associated with an average of 12, 13 and 15 more sedentary minutes per day. Also, being obese and having a heart disease during midlife resulted in considerably more sedentary time in old age. When these factors were present, subjects averaged 22 and 39 minutes more sedentary time per day, respectively! Given the large number of highly sedentary adults and the related risks for health, it is important to develop prevention programs that aim to reduce sedentary time. The results of our study indicate that risk factors for a sedentary lifestyle in old age can be identified years before this behavior manifests. This information can be used to identify groups in an early stage that are at risk of becoming highly sedentary. Our findings, therefore, provide essential information for developing effective prevention strategies to reduce sedentary time and its related adverse health effects.