Presently Recommended Exercise Levels May Be Much More than Needed for Significant Health Benefits

Experts writing in the Canadian Journal of Cardiology challenge physical activity guidelines development groups to update recommendations

Philadelphia, PA, April 4, 2016

International physical activity guidelines generally recommend 150 minutes a week of moderate-to-vigorous intensity physical activity, but a critical review of the literature indicates that just half this level of activity may still lead to marked health benefits, say experts in the Canadian Journal of Cardiology. They challenge physical activity and exercise guidelines development groups to update their recommendations to reflect the evidence.

Physical inactivity is the fourth leading risk factor for global mortality, accounting for approximately 3.2 million deaths annually, according to the World Health Organization. Regular physical activity is acknowledged to be an effective primary and secondary preventive strategy. The evidence points to risk reductions of at least 20-30% for more than 25 chronic medical conditions and premature mortality. However, the amount and intensity of recommended exercise are still hotly debated.

“One of the greatest myths perpetuated within physical activity promotion, the exercise sciences, and exercise medicine is the belief that you need to engage in a minimum of 150 minutes a week of moderate-to-vigorous physical activity to obtain health benefits,” explained Darren E.R. Warburton, PhD, and Shannon S. Bredin, PhD, MSc, of the Cardiovascular Physiology and Rehabilitation Laboratory, University of British Columbia, Vancouver, Canada. “However, the preponderance of evidence simply does not support this contention. There is compelling evidence that health benefits can be accrued at a lower volume and/or intensity of physical activity. These health benefits are seen in both healthy and clinical populations.

“Marked health benefits can be observed in persons living with disability and/or chronic disease with volumes of activity that are well below the 150 minutes per week threshold. Unfortunately, this arbitrary threshold has too often been included in recommendations related to those living with disability and/or chronic medical conditions,” they added.

Dr. Warburton and Dr. Bredin, who were responsible for creating the systematic reviews that informed the 2011 Canadian Physical Activity Guidelines for adults and older adults, attribute the recommendation of the need to reach a minimum of 150 minutes of moderate-to-vigorous intensity physical activity per week in Canada to a translation error introduced since the publication of those reviews. “A simple turn of phrase from ‘should’ to ‘must’ has had significant impact upon the knowledge translation of the evidence. For instance, promotional materials that state explicitly that individuals ‘must’ attain 150 minutes per week to achieve health benefits have emerged, along with other messages that imply (or explicitly state) that health benefits cannot be accrued at lower volumes of activity.”

In the current article, the authors systematically review the latest studies and recommend that:

  • Public health policies should reduce barriers to physical activity participation such that everyone can reap the benefits of physical activity
  • Physical activity/exercise promotion should be part of an integrated approach to enhance healthy lifestyle behaviors
  • The independent health risks of sedentary time (particularly sitting time) should be highlighted
  • Patients should be provided with an individualized prescription (dosage) that considers their unique characteristics and needs

“It is our sincere hope that this article will help address this significant knowledge translation error, such that all Canadians can reap the health benefits of physical activity.” they concluded. “Important, also, is the associated evidence that sedentary time (in particular sitting time) has its own health risk, even for those persons that are physically active. The simple message of ‘Move more and sit less’ is more understandable by contemporary society and based on a strong body of evidence.”

Commenting on this article, James A. Stone, MD, PhD, Clinical Professor of Medicine and Consultant Cardiologist at the University of Calgary, questioned whether these recommendations are “running on empty,” i.e., deriving clinical practice recommendations in the absence of clearly linked high-quality scientific evidence.

“Much of the pertinent information Drs. Warburton and Bredin reference in their review article has only been published in the last few years, and some of it is based on large epidemiologic studies where the available information may be less rigorously researched than the scientific evidence used to produce clinical practical guidelines recommendations,” observed Dr. Stone.

“Have the facts really changed? The argument that a lesser dose of physical activity and exercise can still return significant health benefits needs to be vetted and incorporated into evidence-informed clinical practice guidelines. The time has come to update the message regarding physical activity and exercise,” commented Dr. Stone. “However, practice implementation messages are not the same as evidence-informed clinical practice recommendations derived from high-quality evidence. More specifically, the message that some physical activity is better than none needs to be researched and validated so it can be incorporated into clinical practice guidelines. So, are current guidelines running blind? Clearly, the correct historical answer is an emphatic no. But with rapidly emerging evidence, we need to expeditiously change all clinical practice guidelines when the facts change,” he concluded.

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Notes for editors
“Reflections on Physical Activity and Health: What Should We Recommend?” by Darren E.R. Warburton, PhD, and Shannon S. Bredin, PhD, MSc (doi: 10.1016/j.cjca.2016.01.024)

Editorial: “Canadian Physical Activity Clinical Practice Guidelines Running on Empty?” by James Arthur Stone, MD, PhD (doi: 10.1016/j.cjca.2016.01.037)

Both published in Volume 32, Issue 4 (April 2016) of the Canadian Journal of Cardiology, published by Elsevier.

Full text of these articles is available to credentialed journalists upon request. Contact Eileen Leahy at +1 732 238 3628or cjcmedia@elsevier.com to obtain copies. Journalists who wish to speak with Dr Darren E.R. Warburton may contact him at +1 604 822 4603 or darren.warburton@ubc.ca.  Journalists who wish to reach Dr Stone for comment may contact him at jastone@shaw.ca.

About the Canadian Journal of Cardiology
The Canadian Journal of Cardiology is the official journal of the Canadian Cardiovascular Society. It is a vehicle for the international dissemination of new knowledge in cardiology and cardiovascular science, particularly serving as a major venue for the results of Canadian cardiovascular research and Society guidelines. The journal publishes original reports of clinical and basic research relevant to cardiovascular medicine as well as editorials, review articles, case reports, and papers on health outcomes, policy research, ethics, medical history, and political issues affecting practice.

About the Editor-in-Chief
Editor-in-Chief Stanley Nattel, MD, is Paul-David Chair in Cardiovascular Electrophysiology and Professor of Medicine at the University of Montreal and Director of the Electrophysiology Research Program at the Montreal Heart Institute Research Center.

About the Canadian Cardiovascular Society
The Canadian Cardiovascular Society is the professional association for Canadian cardiovascular physicians and scientists working to promote cardiovascular health and care through knowledge translation, professional development, and leadership in health policy. The CCS provides programs and services to its 1900+ members and others in the cardiovascular community, including guidelines for cardiovascular care, the annual Canadian Cardiovascular Congress, and, with the Canadian Cardiovascular Academy, programs for trainees. More information about the CCS and its activities can be found at www.ccs.ca.

About Elsevier
Elsevier is a world-leading provider of information solutions that enhance the performance of science, health, and technology professionals, empowering them to make better decisions, deliver better care, and sometimes make groundbreaking discoveries that advance the boundaries of knowledge and human progress. Elsevier provides web-based, digital solutions — among them ScienceDirect, Scopus, Research Intelligence and ClinicalKey— and publishes over 2,500 journals, including The Lancet and Cell, and more than 35,000 book titles, including a number of iconic reference works. Elsevier is part of RELX Group, a world-leading provider of information and analytics for professional and business customers across industries. www.elsevier.com

Media contact
Eileen Leahy
Elsevier
+1 732 238 3628
cjcmedia@elsevier.com