frequency of the cardiac cycle is described by the heart rate, which is typically expressed as beats per minute
|Age||Normal resting heart rate|
(beats per minute) 
Heart rate (HR) is how many times a heart beats per minute (bpm). The average bpm for a man or women who does not exercise is 70 bpm. Heart rate varies between people because of fitness, age and genetics.
- Daniel Limmer and Michael F. O'Keefe. 2005. Emergency Care 10th ed. Edward Pearson, Prentice Hall. Upper Saddle River, New Jersey. Page 214.
- "2 easy, accurate ways to measure your heart rate". Mayo Clinic.