Even Low-Level Physical Activity Improves Cardiac Risk

Thomas W. Buford, PhD Assistant Professor, Division of Clinical Research Department of Aging and Geriatric Research, University of Florida College of Medicine Director, Health Promotion Center University of Florida Institute on AgingMedicalResearch.com Interview with:
Thomas W. Buford, PhD
Assistant Professor, Division of Clinical Research
Department of Aging and Geriatric Research, University of Florida College of Medicine
Director, Health Promotion Center
University of Florida Institute on Aging

Medical Research: What is the background for this study? What are the main findings?

Dr. Buford: This study was a cross-sectional analysis of data collected from over 1000 older adults upon their entry into the Lifestyle Interventions and Independence for Elders (LIFE) study. Briefly, participants were recruited into the LIFE Study who were over 70 years of age, sedentary, and had mobility limitations. The objective of this study was to examine, at baseline prior to their participation in the study interventions, the association between daily physical activity habits and risk of major cardiovascular events (i.e. heart attack and coronary-related death). The study utilized accelerometers, devices designed to identify and quantify human movement, to measure participant’s daily activity. Predicted risk of cardiovascular events was determined using a risk score established in the Framingham Heart Study. As identified by accelerometry measures, participants spent on average 70% of their waking hours being sedentary. The major finding of the study, however, was that even extremely low-level activity was associated with an improved cardiovascular risk profile. For every 25-30 minutes a participant was sedentary per day, predicted risk was 1 percent higher. Conversely, But activity identified as slightly above sedentary — which could be light housework or slow walking — was associated with higher levels of the more beneficial kind of cholesterol, HDL, in people with no history of heart disease.

Medical Research: What should clinicians and patients take away from your report?

Dr. Buford: A common refrain we hear is that all individuals should exercise at a moderate-intensity for at least 30 minutes on at least 3 days/week. It’s important to note that for many of these older individuals with mobility limitations, this goal may be unrealistic at least initially. This study indicates that even low-levels of activity may have an important impact in preventing cardiovascular events among older adults. As I mentioned, much of the emphasis has recently been placed on engaging in structured physical exercise. It is becoming increasingly evident, however, that encouraging individuals to at least reduce the amount of time they spend being sedentary may have important cardiovascular benefits. Encouraging people – particularly those with conditions which limit their mobility – to avoid sitting for extend periods of time and taking short breaks to move may have important health implications and be easier for many people to adhere to, at least initially.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Buford: One of the limitations of this study was that all participants were sedentary so the range of activity levels was quite narrow. We hope to follow-up on this study to see how changes in their activity patterns as the study progressed may influence these outcomes. It will be interesting to see if low-intensity activities have the same value once the participants overall level of activity increases. We also hope to utilize these data to examine relationships with the actual occurrence of cardiovascular events, as opposed to using a risk score. More broadly, I think we as scientists and practitioners need to think more closely about the population we are working with in developing physical activity recommendations. We tend to want one-size-fits-all recommendations, but physical activity recommendations may need to more tailored to individual populations. This is an area which I have great interest. Finally, scientists in recent years have become increasingly interested in identifying differences between the lack of exercise/higher intensity activity and chronic engagement in sedentary activities. This is referred to by some as “sitting science”. The idea is that, even if you exercise for an hour in the morning, if you go and sit for 8 hours the rest of the day you have health risks that are independent of the fact that you exercised. I think continuing to increase our understanding of the distinct benefits and limitations of both structured exercise and low-intensity physical activity will have important health implications.

Citation:

Fitzgerald JD, Johnson L, Hire DG, Ambrosius WT, Anton SD, Dodson JA, Marsh AP, McDermott MM, Nocera JR, Tudor-Locke C, White DK, Yank V, Pahor M, Manini TM, Buford TW; the LIFE Study Research Group. Association of Objectively Measured Physical Activity With Cardiovascular Risk in Mobility-limited Older Adults. J Am Heart Assoc. 2015 Feb 18;4(2). pii: e001288. PMID: 25696062.

Link: http://jaha.ahajournals.org/content/4/2/e001288.abstract

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MedicalResearch.com Interview with: Thomas W. Buford, PhD (2015). Even Low-Level Physical Activity Improves Cardiac Risk