New research on exercise's heart health impact

New focus seminar series takes a deep dive into why exercise is vital for heart health

6 September 2022

A new four-part series in the Journal of American Cardiology has highlighted how instrumental exercise is in preventing and managing heart disease.

The series, coordinated by the Institute’s Professor Jason Kovacic, also explores the field of sports cardiology, and gives a unique insight into the inner workings of elite athletes’ hearts.

Professor Jason Kovacic, Executive Director of the Victor Chang Cardiac Research Institute, says: “Exercise doesn’t only change your physical appearance; it also impacts and changes virtually every aspect of our cardiovascular system.

“It’s vital that cardiologists and the wider population understand just how important exercise is to our heart health and how much we should be doing if we want to live long and healthy lives.”

Exercise for Primary and Secondary Prevention of Cardiovascular Disease

In the first part of the focus seminar series, the authors describe just how long-term aerobic exercise changes the heart.

• The heart’s mass and size increase allowing it to pump much more blood.
• This has a flow-on effect on the health of the body’s main arteries.
• It can also lead to changes in skeletal muscles that can trigger an increase in mitochondrial networks – the body’s main powerhouse.
• Exercise can also improve glucose control and increase insulin sensitivity.
• Blood pressure levels can be reduced by up to 7 mm Hg.
• Exercise can also increase the levels of good cholesterol in the body.

Despite the considerable health benefits of exercise, only one in four (24.5%) Australian adults meet physical activity guidelines which recommend 150-300 minutes of moderate-intensity physical activity, or 75-150 minutes of vigorous-intensity physical activity, or an equivalent combination of both, per week. Professor Kovacic says:

“Most Australians know that exercise is good for our health, but the challenge is making people get off the couch and into their exercise gear. We hope that by spelling out the incredible benefits exercise can have on our hearts; it might encourage more Australians to start exercising.

“Even a small increase in aerobic fitness can reduce the chance of developing heart disease and dying prematurely.”

The Athlete’s Heart – Challenges and Controversies

Researchers led by Associate Professor André La Gerche of St. Vincent’s Hospital in Melbourne and the Baker Institute focused on whether the effects of exercise are always beneficial and protective in professional athletes.

They reveal how in some persons, exercise-induced cardiac remodeling (also known as “athlete’s heart”) can contribute to the development of arrhythmias. Regular exercise can promote remodeling of the heart, and significant remodeling is rarely associated with adverse clinical effects, such as atrial fibrillation or other arrhythmias. The authors highlight how extreme cases of an athlete’s heart could potentially evolve into cardiovascular disease. In addition, the knowledge gap between male and female athletes and their cardiovascular health is a major focus of this article.

A/Professor La Gerche says: “Exercise is of course overwhelmingly positive for promoting heart health. Fortunately, it is very rare that exercise appears to promote an increased risk of cardiac death. However, even for these very rare cases, it’s important that we understand who is most at risk and why. This is a rapidly emerging field that we hope will result in safer exercise regimens for all sportspeople.”

Heart Failure with Preserved Ejection Fraction as an Exercise Deficiency Syndrome

The authors discuss an increasingly recognised cause of heart failure – when the heart becomes too stiff and doesn’t relax properly between beats. In medical terms, this is called HFpEF – or heart failure with preserved ejection fraction. The authors hypothesise that cardiovascular fitness and HFpEF (‘stiff heart’) are inversely related; the impacts of a sedentary lifestyle, combined with aging and other comorbidities, may contribute to a stiffer heart and the onset of HFpEF. Heart failure rates begin to increase by age 60, and sedentary lifestyle habits may have already been formed by this age.

Increasing physical activity is associated with greater cardiac mass, stroke volumes, cardiac output and peak oxygen consumption, and overall fewer clinical events. Exercise and cardiorespiratory fitness training can contribute to a better quality of life and can be used as a preventative measure to avoid developing a stiff heart and HFpEF.

Athletic Activity for Patients with Hypertrophic Cardiomyopathy and Other Inherited Cardiovascular Diseases

Individuals with inherited cardiovascular diseases, such as hypertrophic cardiomyopathy (HCM), have historically been restricted from competitive sports due to the risk of sudden cardiac death. The current 2020 AHA/ACC Guidelines for Hypertrophic Cardiomyopathy found that clinician-patient shared decision-making can be used to determine whether an athlete with HCM can safely participate in sports.

The authors explain that, based on previous studies, individuals with HCM or other inherited CVDs can be considered for exercise or sports participation, and that doctors should develop a personalised approach to exercise and competitive sports with these patients.

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For all media enquiries and interview requests, please contact:

Julia Timms
Head, Media & Communications
j.timms@victorchang.edu.au
0457 517 355