How does endurance training affect resting heart rate?

Endurance training has a significant impact on the cardiovascular system, particularly in reducing resting heart rate. When an individual engages in regular endurance activities, such as running, cycling, or swimming, the heart adapts to the increased demands placed on it. This adaptation involves several physiological changes that enhance the heart's efficiency.

One of the key adaptations is an increase in stroke volume, which is the amount of blood ejected by the heart with each contraction. As stroke volume increases, the heart can pump more blood with less effort, meaning it doesn't need to beat as frequently to supply the body with the necessary oxygen and nutrients at rest. This reduced demand leads to a decrease in resting heart rate.

Additionally, endurance training improves the autonomic nervous system's regulation of heart rate. It enhances parasympathetic (rest and digest) activity, which promotes a lower heart rate when at rest. As a result of these adaptations, trained athletes often exhibit a much lower resting heart rate compared to sedentary individuals.

This reduction in resting heart rate is a hallmark of improved cardiovascular fitness and efficiency, making it a key indicator of the positive effects of endurance training on heart health.