Physical Activity, Exercise Training and Heart Failure: Does Intensity Matter?
Heart failure currently affects an estimated 6.2 million US adults1 and approximately 2% of individuals on a global scale.2 According to heart failure exercise guidelines by the American College of Cardiology Foundation and the American Heart Association (AHA), exercise training is considered an effective treatment for chronic heart failure at a class 1 level3 and recognized as a therapeutic approach for stable heart failure. Physical activity and exercise reduce symptoms, improve the quality of life and left ventricle function, lower heart rate response to submaximal exercise, and reverse remodeling in heart failure patients.4-6
Glossary of Terms for Exercise and Heart Failure
To better understand the physiologic benefits of physical activity and exercise, it is helpful to recognize the related terminology and abbreviations.
- Exercise: Planned, structured, and repetitive bodily movement to improve or maintain one or more components of PA.7
- Physical Activity: Any bodily movement produced by skeletal muscles that requires energy expenditure, expressed by Metabolic Equivalents (METs).7
- Heart Rate Reserve (HRR): The range between maximum heart rate (HRmax) and resting heart rate (HRrest), in the formula (HRR = HRmax – HRrest)
- METs: The ratio of the rate of energy expended during an activity to the rate of energy expended at rest.8
- VO2peak: Improve peak exercise capacity or peak oxygen consumption
- MCT: Moderate continuous training
- HIIT: High-intensity interval training
- HFrEF: Heart Failure with Reduced Ejection Fraction
- HFpEF: Heart Failure with Preserved Ejection Fraction
- Repetition Maximum (RM): The most weight a person can lift for a defined number of movements
Benefits from Exercise According to Intensity
Outcomes from studies examining exercise intensity for improved cardiovascular health remain inconclusive with respect to which is most beneficial. Moderate intensity exercise of daily walking for 30 minutes lowers cardiovascular and all-cause mortality by 16%, while higher intensity exercise decreases mortality by 40%.9 These findings were confirmed on a global scale in the Prospective Urban Rural Epidemiological (PURE) study10 and the Copenhagen City Heart Study.11 However, applying an appropriate exercise intensity among individuals with heart failure is more challenging.
Prior studies have shown that exercise may reduce of heart failure. In 2015, Pandey et al.12 demonstrated a dose-response relationship between physical activity and heart failure prevention in which those who engaged in physical activity quantities greater than the current guidelines experienced even greater benefits. Compared to no leisure-time activity, those who engaged in 500, 1000, and 2000 MET-minutes per week had heart failure risk reductions of 10%, 19%, and 35%, respectively.12 These findings suggest, that the greater the quantity of PA, the greater the benefit since no upper or lower threshold effect was observed.12
While physical activity and exercise are beneficial for patients with Heart Failure with Reduced Ejection Fraction (HFrEF) or Heart Failure with Preserved Ejection Fraction (HFpEF), there is a lack of consensus regarding the most effective intensity.13 The etiology and epidemiology differ depending on diagnosis, but the symptoms of reduced exercise tolerance, shortness of breath, and peripheral edema are similar.6 Hsu et al.14 recently explored the effects of high-intensity interval training (HIIT) on left ventricular dimensions and survival for 8 years in heart failure patients and found that survival was improved due to a 14-20% increase in VO2peak.
Exercise and Heart Failure with Reduced Ejection Fraction: HFrEF
The American Heart Association has advised that regular exercise training is safe and does not increase cardiac events in stable HFrEF patients.3 Prior studies have also observed a cardiovascular benefit from exercise among patients with HFrEF. The outcomes of HF-ACTION demonstrated a reduction of 11% in all-cause mortality or all-cause hospitalizations in stable heart failure patients with a median ejection fraction of 25%.5 HIIT and MCT equally improved aerobic capacity in the Study of Myocardial Recovery After Exercise Training in Heart Failure (SMARTEX) Heart Failure Study15 and the SAINTEX-CAD study.16
Exercise and Heart Failure with Preserved Ejection Fraction: HFpEF
Patients with HFpEF experience marked exercise intolerance, dyspnea, and reduced quality of life.17 While standard pharmacological therapy has not improved prognosis or exercise capacity,6 aerobic exercise consistently improves aerobic capacity and quality of life.19 Therefore, endurance and resistance training should be combined to improve exercise capacity and diastolic function.13,18
Donelli da Silveira et al. (2020)20 found HIIT was superior to MCT for improving aerobic capacity in patients with HFpEF. Whereas according to a recent study by Mueller et al. (2021),4 neither HIIT nor MCT were superior to guideline-based physical activity to improve VO2peak in individuals with HFpEF. Although the change in VO2peak was not significantly different after 12 months among the HIIT, MCT, and control groups, a significant improvement in VO2peak was observed from baseline to 3 months for all groups.
Clinical Implications: Structured Exercise Training in Chronic Heart Failure
Exercise training should be viewed as complementary rather than an alternative treatment in stable heart failure.6 Patients should be advised that the goal is to gradually integrate physical activity into their daily lives. Optimal exercise tolerance may take months to develop but it starts with taking the first toward heart health. Patients should incorporate resistance training in addition to endurance to improve stability, coordination, strengthen muscles and prevent loss of muscle strength.
|Training Progress||Week||Target||MCT||Modified HIIT||Resistence|
start low, go slow
|week 1-2||Frequency||2-3 times per week, ideally 2 sessions per day||2 times per week|
|Time||15 minutes, symptom, comordibity guilded||15 repetitions 1-2 times|
|Intensity||40-50% Vo2peak||<30% 1 RPM|
when beginning is well tolerated
|week 3-4||Frequency||Increasing up to 3-4 times per week||Increase to 15-20 repetitions|
|week 5-7||Time||Duration from 15-20 minutes to 30-40 minutes||Alternate short intervals of higher intensity exercise for 10 secs of 50-70% VO2peak, longer recovery of 3 minutes at 40% VO2peak. Increasing duration to 15-20 mins, then 30-45 mins.|
|week 8-12||Intensity||Increase to 50%-60%, then 60-70% VO2peak||Increase duration of intervals (to 2 min) and decrease recovery (to 2-3 min).||Increase intensity (30-50% 1-RM)|
when the progression phase is well tolerated
|12 weeks or longer||Goals||60-70% VO2peak||Interval intensity 70-80% VO2peak. Recovery 50% VO2peak||Increase intensity (40-60% 1-RM, 15-20 repetitions)|
Table courtesy of Schindler MJ, Adams V, Halle M. Exercise in heart failure-what is the optimal dose to improve pathophysiology and exercise capacity? Curr Heart Fail Rep. 2019;16(4):98-107. doi:10.1007/s11897-019-00428-z
It is important to cool down after exercising by slowly walking for two or three minutes. Exercising at the same time each day helps establish a habit. Minimizing barriers to exercise and avoiding walking great distances ensures a safe return journey. Lastly, if extreme shortness of breath, dizziness, chest discomfort or weakness occur, patients should be advised to stop exercising and contact a primary care provider.
Heart Failure Resources
- Heart failure patient rescoures – interactive tool and handouts
- Sex Difference in the Management of Heart Failure 0.75 CE course
- Symptoms and Skeletal Muscle in Persons with Heart Failure with Preserved Ejection Fraction 0.25 CE course
- Centers for Disease Control and Prevention. Content source: National Center for Chronic Disease Prevention and Health Promotion, Division for Heart Disease and Stroke Prevention Page last reviewed: September 8, 2020. Accessed 10/10/21
- Virani SS, Alonso A, Benjamin EJ, et al. Heart disease and stroke statistics-2020 update: a report from the American Heart Association. Circulation. 2020;141(9):e139-e596. doi:10.1161/CIR.0000000000000757
- Yancy, C. W., Jessup, M., Bozkurt, B., Butler, J., Casey, D. E., Jr, Colvin, M. M., Drazner, M. H., Filippatos, G. S., Fonarow, G. C., Givertz, M. M., Hollenberg, S. M., Lindenfeld, J., Masoudi, F. A., McBride, P. E., Peterson, P. N., Stevenson, L. W., & Westlake, C. (2017). 2017 ACC/AHA/HFSA focused update of the 2013 ACCF/AHA guideline for the management of heart failure: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Failure Society of America.
- Mueller S, Winzer EB, Duvinage A, et al. Effect of high-intensity interval training, moderate continuous training, or guideline-based physical activity advice on peak oxygen consumption in patients with heart failure with preserved ejection fraction: a randomized clinical trial. JAMA. 2021;325(6):542-551. doi:10.1001/jama.2020.26812
- O’Connor CM, Whellan DJ, Lee KL, et al. Efficacy and safety of exercise training in patients with chronic heart failure: HF-ACTION randomized controlled trial. JAMA. 2009;301(14):1439-1450. doi:10.1001/jama.2009.454
- Schindler MJ, Adams V, Halle M. Exercise in heart failure-what is the optimal dose to improve pathophysiology and exercise capacity? Curr Heart Fail Rep. 2019;16(4):98-107. doi:10.1007/s11897-019-00428-z
- Caspersen, C. J., Powell, K. E., & Christenson, G. M. (1985). Physical activity, exercise, and physical fitness: Definitions and distinctions for health related research. Public Health Reports, 100(2), 126–131.
- U.S. Department of Health and Human Services. (2018). Physical activity guidelines for Americans (2nd ed.). PDF
- Wen CP, Wai JP, Tsai MK, et al. Minimum amount of physical activity for reduced mortality and extended life expectancy: a prospective cohort study. Lancet. 2011;378(9798):1244-1253. doi:10.1016/S0140-6736(11)60749-6
- Lear SA, Hu W, Rangarajan S, et al. The effect of physical activity on mortality and cardiovascular disease in 130 000 people from 17 high-income, middle-income, and low-income countries: the PURE study. Lancet. 2017;390(10113):2643-2654. doi:10.1016/S0140-6736(17)31634-3
- Schnohr P, Marott JL, Jensen JS, Jensen GB. Intensity versus duration of cycling, impact on all-cause and coronary heart disease mortality: the Copenhagen City Heart Study. Eur J Prev Cardiol. 2012;19(1):73-80. doi:10.1177/1741826710393196
- Pandey A, Garg S, Khunger M, et al. Dose-Response Relationship Between Physical Activity and Risk of Heart Failure: A Meta-Analysis. Circulation. 2015;132(19):1786-1794. doi:10.1161/CIRCULATIONAHA.115.015853
- Ponikowski P, Voors AA, Anker SD, et al. 2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: the task force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC) Developed with the special contribution of the Heart Failure Association (HFA) of the ESC. Eur Heart J. 2016;37(27):2129-2200. doi:10.1093/eurheartj/ehw128
- Hsu CC, Fu TC, Yuan SS, et al. High-intensity interval training is associated with improved long-term survival in heart failure patients. J Clin Med. 2019;8(3):409. doi:10.3390/jcm8030409
- Karlsen T, Videm V, Halle M, et al. Baseline and exercise predictors of VO2peak in systolic heart failure patients: results from SMARTEX-HF. Med Sci Sports Exerc. 2020;52(4):810-819. doi:10.1249/MSS.0000000000002193
- Conraads VM, Pattyn N, De Maeyer C, et al. Aerobic interval training and continuous training equally improve aerobic exercise capacity in patients with coronary artery disease: the SAINTEX-CAD study. Int J Cardiol. 2015;179:203-210. doi:10.1016/j.ijcard.2014.10.155
- Beckers PJ, Gevaert AB. High intensity interval training for heart failure with preserved ejection fraction: high hopes for intense exercise. Eur J Prev Cardiol. 2020;27(16):1730-1732. doi:10.1177/2047487320910294
- Zhang S, Zhang J, Liang C, Li X, Meng X. High-intensity interval training for heart failure with preserved ejection fraction: A protocol for systematic review and meta-analysis. Medicine (Baltimore). 2020;99(27):e21062. doi:10.1097/MD.0000000000021062
- Fukuta H, Goto T, Wakami K, Kamiya T, Ohte N. Effects of exercise training on cardiac function, exercise capacity, and quality of life in heart failure with preserved ejection fraction: a meta-analysis of randomized controlled trials. Heart Fail Rev. 2019;24(4):535-547. doi:10.1007/s10741-019-09774-5
- Donelli da Silveira A, Beust de Lima J, da Silva Piardi D, et al. High-intensity interval training is effective and superior to moderate continuous training in patients with heart failure with preserved ejection fraction: A randomized clinical trial. Eur J Prev Cardiol. 2020;27(16):1733-1743. doi:10.1177/2047487319901206