Knowledge Base

Effects of endurance training on the heart

Endurance training is widely recognized for its positive effects on health and well-being. Specifically, its effects on the heart, both in terms of heart performance and biological structure, are of particular scientific interest. This article sheds light on the underlying mechanisms and the resulting benefits of regular endurance training on the heart.

Heart Performance and Endurance Training

Endurance training leads to significant improvements in cardiovascular efficiency, especially by increasing maximum oxygen uptake (VO2max). This is a key indicator of cardiorespiratory fitness, reflecting the heart’s ability to transport blood and thus oxygen to the working muscles. Research shows that an increased VO2max is associated with more efficient heart function and a reduced risk of cardiovascular diseases. Hambrecht et al. (2000) demonstrated in their study that just four weeks of targeted endurance training are enough to achieve significant improvements in left ventricular function, indicating enhanced heart performance.

Improvement of Left Ventricular Function

Left ventricular function refers to the functioning of the left ventricle of the heart, responsible for pumping oxygen-rich blood from the heart throughout the body. This function is crucial for the efficiency of the cardiovascular system and includes two main aspects: systolic and diastolic function.

Systolic Function: This aspect concerns the ability of the left ventricle to contract and pump blood into the aorta and then throughout the body. Systolic function is often measured by the ejection fraction, a measure of the percentage of blood volume that is ejected from the ventricle with each heartbeat. A high ejection fraction indicates effective contraction and thus good systolic function.

Diastolic Function: This refers to the ability of the left ventricle to relax and fill with blood from the left atrium after a contraction. Adequate diastolic function is essential for sufficient filling of the ventricle and thus for the volume of blood that can be pumped with the next contraction. Problems with diastolic function can lead to heart failure, even if systolic function is normal.

Biological Structure of the Heart and Adjustments through Endurance Training

In addition to performance enhancement, endurance training also induces structural changes to the heart. Physiological cardiac hypertrophy (increase in heart muscle mass) is a typical adjustment to regular endurance training. This form of hypertrophy fundamentally differs from pathological hypertrophy caused by high blood pressure and is considered health-promoting. It leads to enhanced pumping ability of the heart without increasing the risk of cardiovascular diseases. Neilan et al. (2006) found that endurance athletes show a significant increase in heart muscle mass, correlating with improved cardiac function.

These adjustments are a result of the increased demands on the heart during regular endurance exercise. The heart responds to the increased load with more efficient blood supply and a stronger muscular structure, overall leading to improved cardiovascular health.


The present evidence highlights the diverse positive effects of endurance training on the heart. By enhancing cardiorespiratory fitness and inducing healthy structural adjustments of the heart muscle, endurance training significantly contributes to the prevention of cardiovascular diseases. These findings are particularly relevant at a time when sedentary lifestyles and associated health risks are on the rise. Endurance training thus provides an effective strategy for promoting heart health and enhancing overall quality of life.


Hambrecht, R. et al. (2000). “Effects of Endurance Training on Mitochondrial Ultrastructure and Fiber Type Distribution in Skeletal Muscle of Patients with Stable Chronic Heart Failure.” Journal of the American College of Cardiology.

Neilan, T.G. et al. (2006). “Myocardial Adaptations to Exercise Training in Humans: Insights from Cardiovascular Magnetic Resonance.” Exercise and Sport Sciences Reviews.

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