Endurance training positively affects the cardiovascular system by strengthening the heart and improving blood circulation. This type of training enhances the heart's ability to pump blood more efficiently, reducing the resting heart rate and lowering blood pressure over time. As a result, endurance athletes often show increased stroke volume, meaning the heart pumps more blood with each beat. Additionally, it promotes higher levels of good cholesterol (HDL) and boosts overall cardiovascular health, reducing the risks of heart disease.