Heart rate, or heart pulse, is the speed of the heartbeat measured by the number of contractions of the heart per unit of time — typically beats per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excrete carbon dioxide.he basal or resting heart rate (HR rest) is defined as the heart rate when a person is awake, in a neutrally temperate environment, and has not undergone any recent exertion or stimulation, such as stress or surprise. The typical resting heart rate in adults is 60–100 beats per minute (bpm).