Elsevier

Mayo Clinic Proceedings

Volume 90, Issue 11, November 2015, Pages 1533-1540
Mayo Clinic Proceedings

Special article
Less Sitting, More Physical Activity, or Higher Fitness?

https://doi.org/10.1016/j.mayocp.2015.08.005Get rights and content

Abstract

Epidemiological studies have found that time spent in sedentary behaviors, levels of physical activity, and cardiorespiratory fitness are all associated with mortality rates. They are also related to the risks of obesity, type 2 diabetes mellitus, hypertension, cardiovascular disease, aging-associated frailty, and cancer. The evidence is such that the National Institutes of Health recently launched a new Common Fund initiative aimed at identifying the molecular transducers of adaptation to physical activity in various tissues and organs. It has been estimated that 9.4% of all 57 million deaths in the world in 2008 could be attributed to physical inactivity, which translates into more than 5 million deaths worldwide. Physical inactivity has a deleterious effect that is comparable to smoking and obesity. Importantly, this global estimate relates to levels of physical activity and does not take into account sedentary behavior and cardiorespiratory fitness. Currently, there are national and international guidelines for physical activity level that are highly concordant. The weekly recommendations include 150 minutes of moderate-intensity activity, 75 minutes of vigorous-intensity activity, or some combination of moderate and vigorous activity with 2 days of resistance exercise. However, these guidelines offer no recommendations regarding sedentary time or goals for cardiorespiratory fitness levels. It will be increasingly important for disease prevention, successful aging, and reduction of premature mortality to broaden the focus of the public health message to include not only more physical activity but also less sitting and higher cardiorespiratory fitness. We briefly review the evidence and discuss key issues to be addressed to make this approach a reality.

Section snippets

Sitting and All-Cause Mortality

The independent role of sedentary behavior as a risk factor for poor health and premature mortality has received considerable attention in recent years.6, 7 Sedentary behavior has been defined as any waking behavior characterized by an energy expenditure that is less than or equal to 1.5 times the resting metabolic rate while in a sitting or reclining posture.8 It has been operationalized in several ways in scientific studies, including the use of television viewing as a marker of sedentary

Physical Activity and All-Cause Mortality

The role of physical activity in the prevention of chronic disease and premature mortality is well established.2 More than 50 years of systematic epidemiological and intervention research contributed to the development of the 2008 Physical Activity Guidelines for Americans,4 which call for 150 minutes of moderate activity, 75 minutes of vigorous activity, or some combination of moderate and vigorous activity. Similar guidelines have been promoted by other countries and by the World Health

Cardiorespiratory Fitness and All-Cause Mortality

The first studies on cardiorespiratory fitness and mortality were published more than 30 years ago.23 Cardiorespiratory fitness is defined here as either maximal oxygen uptake or maximal work capacity and is measured typically with a treadmill or cycle ergometer test. Cardiorespiratory fitness can also be estimated by submaximal exercise tests. The first study to use maximal exercise tests with all-cause mortality as the outcome was published in 1989.24 The results revealed that low

Intrinsic and Acquired Cardiorespiratory Fitness

Low cardiorespiratory fitness is a powerful predictor of health problems and premature death. To better understand the public health implications of this observation, one would need to untangle the intrinsic and acquired components of cardiorespiratory fitness at the individual level. The intrinsic level of cardiorespiratory fitness can be measured by testing for maximal oxygen uptake adjusted for body mass in a person who has a life history of being sedentary with no history of exercise

Implications of the Evidence for Public Health Recommendations

In the earlier sections of this article, we provided succinct reviews of the scientific evidence that sedentary behavior, regular physical activity, and cardiorespiratory fitness have strong associations with premature mortality (Figure 2). Low cardiorespiratory fitness may be the strongest of these risk factors because the associations with mortality indicators remain strong even after adjustment for physical activity level. We certainly have ample evidence that cardiorespiratory fitness has a

Conclusion

This review illustrates the importance of sedentary behavior, physical activity level, and cardiorespiratory fitness to health outcomes and premature death. There are associations among these variables, but there also is evidence supporting their independence as health-related variables. Additional research is needed to address several outstanding questions that would help clarify their public health implications. We encourage health authorities and funding agencies to focus more attention on

References (38)

  • Sedentary Behaviour Research Network

    Standardized use of the terms “sedentary” and “sedentary behaviours”

    Appl Physiol Nutr Metab

    (2012)
  • A. Grøntved et al.

    Television viewing and risk of type 2 diabetes, cardiovascular disease, and all-cause mortality: a meta-analysis

    JAMA

    (2011)
  • A. Koster et al.

    Association of sedentary time with mortality independent of moderate to vigorous physical activity

    PLoS One

    (2012)
  • J.Y. Chau et al.

    Daily sitting time and all-cause mortality: a meta-analysis

    PLoS One

    (2013)
  • R.R. Pate et al.

    The evolving definition of “sedentary.”

    Exerc Sport Sci Rev

    (2008)
  • M.S. Tremblay et al.

    Physiological and health implications of a sedentary lifestyle

    Appl Physiol Nutr Metab

    (2010)
  • B.B. Gibbs et al.

    Definition, measurement, and health risks associated with sedentary behavior

    Med Sci Sports Exerc

    (2015)
  • P.T. Katzmarzyk et al.

    Sitting time and mortality from all causes, cardiovascular disease, and cancer

    Med Sci Sports Exerc

    (2009)
  • R.S. Paffenbarger et al.

    A history of physical activity, cardiovascular health and longevity: the scientific contributions of Jeremy N Morris, DSc, DPH, FRCP

    Int J Epidemiol

    (2001)
  • Cited by (0)

    Potential Competing Interests: Dr Bouchard has received book royalties from Elsevier, CRC Press, and Human Kinetics; has received honoraria for lectures from Gatorade, Inc, DASA SA, and Biogenetika; has served on advisory boards for Pathway Genomics, Nike, Inc, and Weight Watchers International, Inc; has received research funding from the National Institutes of Health (grant HL-45670) and the King Faisal Foundation of Saudi Arabia; and is partially funded by the John W. Barton Sr Chair in Genetics and Nutrition.

    Dr Blair has received book royalties from Human Kinetics; has received honoraria for lectures and consultations from scientific, educational, and lay groups that are donated to the University of South Carolina or not-for-profit organizations; is a consultant on research projects with the University of Texas Southwestern Medical School and the University of Miami; and has received research grants from BodyMedia, Inc, The Coca-Cola Company, the National Institutes of Health, and the Department of Defense.

    Dr Katzmarzyk is supported in part by the Marie Edana Corcoran Endowed Chair in Pediatric Obesity and Diabetes and grant 1 U54 GM104940 from the National Institute of General Medical Sciences of the National Institutes of Health, which funds the Louisiana Clinical and Translational Science Center.

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