Ideal Exercise Prescription for Cardiovascular Health
Thank you to Elizabeth Moxley, PhD, RN, BS for this article on physical activity and exercise prescription.
What is the ideal exercise prescription? It is well established that exercise improves cardiovascular and all-cause mortality, although an ideal exercise dose is unknown.1-2 What is known, and perhaps most concerning, is that physical inactivity has increased3-4 in recent decades to the extent that it affects all strata of society: every age, culture, race, gender, and ethnic background.5
Approximately 80% of U.S. adults and 81% of adolescents fail to meet physical activity requirements established by recent guidelines of a minimum of 150 to 300 minutes per week of moderate-intensity aerobic and muscle strengthening activity.6-7 This lack of adequate physical activity was found to contribute to at least 8% of deaths in the United States, with a significant association between physical activity and mortality in adults aged 40 to 70. In other words, physically inactive adults between 40 to 70 years of age had a greater risk of premature death than those who maintained a quantity of physical activity consistent with the guidelines.8
Quantities of physical activity consistent with the guidelines, or the ‘sweet spot,’ are well-established for longevity and cardiovascular health.9 Physical activity is a known primary modifiable risk factor for CVD10 and a leading risk factor for mortality.11 Engaging in adequate quantities of physical activity decreases the risk for CVD, type 2 diabetes, breast and colon cancer, bone and joint problems, and other comorbidities.12-13 While a “too much exercise hypothesis”14 recently emerged in which adverse cardiovascular outcomes result from exercise performed at too high an intensity or too great a volume,15 the greater risk to the U.S. population is that of not enough exercise. Since most Americans engage in too little exercise,16 the message that physical activity and exercise are essential for improving health and decreasing cardiovascular risk should always be a priority for clinicians and their patients.17 The primary concern for most individuals is to determine safe and sustainable exercise levels that can feasibly be incorporated.2
Exercise and Physical Activity
While many people thoroughly enjoy exercise or being physically active, exercise and physical activity are distinct. Physical activity is any bodily movement produced by skeletal muscles that requires energy expenditure, such as playing, working, doing chores, and participating in recreation.19 By comparison, exercise is planned, structured, and repetitive bodily movement performed to improve or maintain one or more components of physical activity.18
While used interchangeably, physical inactivity and sedentary behavior are not the same. Physical inactivity refers to not participating in the recommended quantity of regular physical activity .20 Sedentary behavior is a behavior characterized by a low level of energy expenditure (sitting, reclining, or lying down) or a low level of movement as measured by devices that assess movement or posture.6,21
Ideal Exercise Session: Where to Begin?
A current priority for achieving cardiovascular fitness is finding a time-efficient amount of exercise. A variety of barriers, however, keep individuals from meeting these goals, including limited access to a safe location for exercise,22 age, chronic disease, or knowledge about starting an exercise routine.
Some individuals are deterred by the term ‘exercise’ itself. For some individuals, ‘exercise’ may bring to mind stressful situations such as group fitness classes, activities at an intensity for which they may be ill-prepared, a previous exercise experience that was unwelcoming, or locations where the equipment is unfamiliar. Replacing the word ‘exercise’ with ‘activity’ or ‘movement’ may help to overcome these potential barriers. The important thing is to have individuals increase their level of activity; recent findings have progressively demonstrated that when it comes to exercise, everything counts,23 and that increasing intensity may more efficiently improve fitness.
Importance of Intensity in Exercise
Intensity was observed as an essential component of fitness and a strong predictor of morbidity and mortality in the Studies Targeting Risk Reduction Interventions through Defined Exercise-Aerobic Training and/or Resistance Training (STRRIDE-AT/RT).24 STRRIDE-AT/RT revealed vigorous-intensity exercise more efficiently improved fitness than moderate-intensity exercise. When exercise was performed at a fixed intensity and varied dose, a greater improvement in VO2 peak (peak oxygen uptake) was observed than when exercise was performed at a varied intensity and fixed total dose.24
The American Heart Association and the American College of Cardiology recommend less frequent exercise sessions (3-4 times per week) for longer durations (30-40 minutes).25 According to the American College of Sports Medicine (ACSM)26 however, a decreased trend has occurred in the guidelines for exercise intensity since 1975—a trend paralleling the progressive increase in sedentary behavior. The 1975 ACSM recommendations to improve exercise intensity were consistent with a maximal amount of oxygen consumed (VO2max) of 70%.26 By 1978, these recommendations had decreased to 50% VO2max,27 with a subsequent decrease to 40% to 50% VO2max by 1990,28 at which time moderate-intensity exercise was considered sufficient to improve fitness.29 The current American College of Sports Medicine30 recommendations for exercise are consistent with the United States Department of Health and Human Services Guidelines recommending at least moderate intensity exercise or 46-63% VO2max.
Measuring Physical Activity Intensity
Intensity is measured in either absolute or in relative terms.31,32 Metabolic equivalents, or METs20, are a measure of absolute intensity and reflect energy expenditure during rest.20 An activity requiring 10 METs is equivalent to 10 times the energy required at rest. The CDC33 and the ACSM30 provide useful information to determine intensity in their recent guidelines. For example, light intensity activity requires 1.6-2.9 METs and includes slow walking, washing dishes, or playing an instrument. Moderate intensity (between 3.0-5.9 METs) includes brisk walking at about 3 miles per hour, slower bike riding, or gardening. Vigorous activity of 6 or more METs includes race walking, aerobic dancing, hoeing a garden, or biking uphill. While it is easy to carry on a conversation during moderate-intensity exercise, conversations become more difficult when exercising at a vigorous intensity.
Time Efficient Exercise Sessions at Various Durations and Intensities
The benefits of workouts that last for a short duration of time – albeit not always at a vigorous intensity – have demonstrated favorable cardiovascular outcomes.9, 34-38 According to Saint-Maurice34, who recently examined physical activity and the rate of mortality data for Americans, as little as 10 minutes per day of additional low- to moderate-intensity exercise is sufficient to prevent more than 111,000 premature deaths each year. Paluch et al.9 recently demonstrated the optimal step count for longevity is 8,000-10,000/day for those less than 60 years of age. However, if the individual is 60 years or older, 6,000-8,000 steps/day is necessary.
Several recent studies have demonstrated improvement in fitness from workouts of vigorous intensity for less than a minute. In 2017, Allison et al.35found that sedentary women were able to increase fitness by approximately 12% in six weeks after completing three 20-second bouts of stair climbing with several minutes of rest between sessions. Jenkins et al.36 demonstrated the benefit of the ‘exercise snack’ – a series of brief workouts performed throughout the day – to improve cardiometabolic health. College students who climbed three flights of stairs as fast as they could improved their fitness by about 5% in six weeks. Islam et al.37 also recently demonstrated cardiometabolic health benefits from ‘exercise snack’ involving physical activity performed for 1 minute or less.
Clinical Takeaways for An Exercise Prescription
- Finding an exercise prescription that fits an individual requires flexibility. Exercise sessions can be divided into:
- several smaller sessions with higher and lower intensities39 interspersed throughout the day, like one- or two-minute walks, short bursts of fast walking, climbing stairs, carrying shopping bags, gardening
- long and continuous 30-minute sessions, as long as 150 minutes of moderate exercise are accumulated.40
- Replacing the word ‘exercise’ with ‘activity’ or ‘movement’ may help to overcome these potential barriers.
- Even weekend warriors or those who exercise only on weekends are less likely to die prematurely than those who rarely exercised at all.38
When it comes to the ideal exercise prescription, the perfect dose may be whatever best fits into the individual’s lifestyle to maintain a quantity of physical activity consistent with the recommended guidelines. And while increases in intensity improve cardiometabolic health and fitness,40 any amount of exercise is better than nothing at all.2
- Kim MH, Sung JH, Jin MN, et al. Impact of Physical Activity on All-Cause Mortality According to Specific Cardiovascular Disease.. Front Cardiovasc Med. 2022;9:811058. Published 2022 Feb 4. doi:10.3389/fcvm.2022.811058
- Moxley E, Habtzghi D. A Systematic Review Comparing Dose Response of Exercise on Cardiovascular and All-Cause Mortality. Home Health Care Management & Practice. 2019;31(4):263-273. doi:10.1177/1084822319831929
- Guthold R, Stevens GA, Riley LM, Bull FC. Worldwide trends in insufficient physical activity from 2001 to 2016: a pooled analysis of 358 population-based surveys with 1·9 million participants [published correction appears in Lancet Glob Health. 2019 Jan;7(1):e36]. Lancet Glob Health. 2018;6(10):e1077-e1086. doi:10.1016/S2214-109X(18)30357-7
- Guthold R, Stevens GA, Riley LM, Bull FC. Global trends in insufficient physical activity among adolescents: a pooled analysis of 298 population-based surveys with 1·6 million participants. Lancet Child Adolesc Health. 2020;4(1):23-35. doi:10.1016/S2352-4642(19)30323-2
- Centers for Disease Control and Prevention (CDCa). Adult Physical Inactivity Prevalence Maps by Race/Ethnicity. Updated 2022. Accessed July 6, 2022.
- U.S. Department of Health and Human Services. (2018). Physical Activity Guidelines for Americans (2nd ed.). Updated 2018. Accessed July 6, 2022.
- Centers for Disease Control and Prevention (CDCb). About Physical Activity. Updated 2022. Accessed July 6, 2022.
- Carlson, S.A. Percentage of Deaths Associated with Inadequate Physical Activity in the United States. (2018).Centers for Disease Control and Prevention.
- Paluch AE, Bajpai S, Bassett DR, et al. Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts. Lancet Public Health. 2022;7(3):e219-e228. doi:10.1016/S2468-2667(21)00302-9
- Ross R, Blair SN, Arena R, et al. Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association. Circulation. 2016;134(24):e653-e699. doi:10.1161/CIR.0000000000000461
- World Health Organization. Global recommendations on physical activity for health. 2010. Accessed July 6, 2022
- Mielke GI, Menezes AMB, DA Silva BGC, et al. Associations between Device-measured Physical Activity and Cardiometabolic Health in the Transition to Early Adulthood. Med Sci Sports Exerc. 2021;53(10):2076-2085. doi:10.1249/MSS.0000000000002696
- Ainsworth BE, Macera CA. Promoting physical activity in a public health context. J Sport Health Sci. 2018;7(1):1-2. doi:10.1016/j.jshs.2017.10.004
- Eijsvogels TM, Molossi S, Lee DC, Emery MS, Thompson PD. Exercise at the Extremes: The Amount of Exercise to Reduce Cardiovascular Events. J Am Coll Cardiol. 2016;67(3):316-329. doi:10.1016/j.jacc.2015.11.034
- Kim JH, Baggish AL. Strenuous exercise and cardiovascular disease outcomes. Curr Atheroscler Rep. 2017;19(1):1. doi:10.1007/s11883-017-0636-3
- World Health Organization. WHO calls for better and fairer opportunities for physical activity to improve health. Updated 2021. Accessed April 22, 2022.
- Solomon TP, Thyfault JP. Type 2 diabetes sits in a chair. Diabetes Obes Metab. 2013;15(11):987-992. doi:10.1111/dom.12105
- Caspersen CJ, Powell KE, Christenson GM. Physical activity, exercise, and physical fitness: definitions and distinctions for health-related research. Public Health Rep. 1985;100(2):126-131
- World Health Organization (2018). Global strategy on diet, physical activity and health.
- Tremblay MS, Aubert S, Barnes JD, et al. Sedentary behavior research network (SBRN) – terminology consensus project process and outcome. Int J Behav Nutr Phys Act. 2017;14(1):75. Published 2017 Jun 10. doi:10.1186/s12966-017-0525-8
- Pate RR, Pratt M, Blair SN, et al. Physical activity and public health. A recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA. 1995;273(5):402-407. doi:10.1001/jama.273.5.402
- Webber-Ritchey KJ, Moxley E, Hwang S, et al. Perceived neighborhood characteristics and parental role in physical activity of African American Youth. Journal of Nursing Practice Applications and Reviews of Research. 2021;11(1):27-42.
- Chastin SFM, McGregor DE, Biddle SJH, et al. Striking the Right Balance: Evidence to Inform Combined Physical Activity and Sedentary Behavior Recommendations. J Phys Act Health. 2021;18(6):631-637. Published 2021 May 14. doi:10.1123/jpah.2020-0635
- Slentz CA, Houmard JA, Johnson JL, et al. Inactivity, exercise training and detraining, and plasma lipoproteins. STRRIDE: a randomized, controlled study of exercise intensity and amount. J Appl Physiol (1985). 2007;103(2):432-442. doi:10.1152/japplphysiol.01314.2006
- Eckel RH, Jakicic JM, Ard JD, et al. American College of Cardiology/American Heart Association task force on practice guidelines. Circulation. 2014;129(25suppl 2):S76-99. doi:10.1161/01.cir.0000437740.48606.d1.
- American College of Sports Medicine. Position statement on the recommended quantity and quality of exercise for developing and maintaining fitness in healthy adults. Med Sci Sports Exerc.1975;10:vii-x.
- American College of Sports Medicine position statement on the recommended quantity and quality of exercise for developing and maintaining fitness in healthy adults. Med Sci Sports Exerc.1978;10:vii-x.
- American College of Sports Medicine Position statement on the recommended quantity and quality of exercise for developing and maintaining fitness in healthy adults. Med Sci Sports Exerc.1990;10:vii-x.
- American College of Sports Medicine. ACSM’s guidelines for exercise testing and prescription. Philadelphia, PA: Lippincott Williams & Wilkins; 2017.
- American College of Sports Medicine. ACSM’s guidelines for exercise testing and prescription. Philadelphia: Wolters Kluwer, 2021.
- Strath SJ, Kaminsky LA, Ainsworth BE, et al. Guide to the assessment of physical activity: Clinical and research applications: a scientific statement from the American Heart Association. Circulation. 2013;128(20):2259-2279. doi:10.1161/01.cir.0000435708.67487.da
- Blair SN, Kohl HW, Gordon NF, Paffenbarger RS Jr. How much physical activity is good for health?. Annu Rev Public Health. 1992;13:99-126. doi:10.1146/annurev.pu.13.050192.000531
- Centers for Disease Control and Prevention. Measuring physical activity intensity. Page last updated June 3, 2022. https://www.cdc.gov/physicalactivity/basics/measuring/index.html. Accessed July 6, 2022.
- Saint-Maurice PF, Graubard BI, Troiano RP, et al. Estimated number of deaths prevented through increased physical activity among US adults. JAMA Intern Med. 2022;182(3):349-352. doi:10.1001/jamainternmed.2021.7755
- Allison MK, Baglole JH, Martin BJ, Macinnis MJ, Gurd BJ, Gibala MJ. Brief intense stair climbing improves cardiorespiratory fitness [published correction appears in Med Sci Sports Exerc. 2017 Mar;49(3):626]. Med Sci Sports Exerc. 2017;49(2):298-307. doi:10.1249/MSS.0000000000001188
- Jenkins EM, Nairn LN, Skelly LE, Little JP, Gibala MJ. Do stair climbing exercise “snacks” improve cardiorespiratory fitness? Appl Physiol Nutr Metab. 2019;44(6):681-684. doi:10.1139/apnm-2018-0675
- Islam H, Gibala MJ, Little JP. Exercise snacks: a novel strategy to improve cardiometabolic health. Exerc Sport Sci Rev. 2022;50(1):31-37. doi:10.1249/JES.0000000000000275
- O’Donovan G, Lee IM, Hamer M, Stamatakis E. Association of “Weekend Warrior” and Other Leisure Time Physical Activity Patterns With Risks for All-Cause, Cardiovascular Disease, and Cancer Mortality [published correction appears in JAMA Intern Med. 2022 May 1;182(5):579]. JAMA Intern Med. 2017;177(3):335-342. doi:10.1001/jamainternmed.2016.8014
- Saint-Maurice PF, Troiano RP, Matthews CE, Kraus WE. Moderate-to-vigorous physical activity and all-cause mortality: do bouts matter? [published correction appears in J Am Heart Assoc. 2018 Dec 4;7(23):e03713]. J Am Heart Assoc. 2018;7(6):e007678. Published 2018 Mar 22. doi:10.1161/JAHA.117.007678
- Ekelund U, Tarp J, Fagerland MW, et al. Joint associations of accelero-meter measured physical activity and sedentary time with all-cause mortality: a harmonised meta-analysis in more than 44 000 middle-aged and older individuals. Br J Sports Med. 2020;54(24):1499-1506. doi:10.1136/bjsports-2020-103270