Heart rate persons with coronary artery disease. The heart rate is rhythmically generated by the sinoatrial node. It is also influenced by central factors through sympathetic and parasympathetic nerves. Nervous influence over the heartrate is centralized within the two paired cardiovascular centres of the medulla oblongata. The cardioaccelerator regions stimulate activity via sympathetic stimulation of the cardioaccelerator nerves, and the cardioinhibitory centers decrease heart activity via parasympathetic stimulation as one component of the vagus nerve. During rest, both centers provide slight stimulation to the heart, contributing to autonomic tone. This is a similar concept to tone in skeletal muscles. Normally, vagal stimulation
Heart rate factors in resting heart rate (HR) to calculate target heart rate (THR), using a range of 50–85% intensity: Equivalently, "Example for someone with a HR of 180 and a HR of 70 (and therefore a HR of 110):" An alternative to the Karvonen method is the "Zoladz method", which derives exercise zones by subtracting values from HR: "Example for someone with a HR of 180:" "Heart rate recovery" (HR) is the reduction in heart rate at peak exercise and the rate as measured after a cool-down period of fixed duration. A greater reduction in heart rate after exercise during the