The human heart beats approximately 70 to 85 times per minute in the average adult, with a notable difference between the genders. The average adult male heart rate is between 70 and 72 beats per minute, while there average for adult women is between 78 and 82 beats. This difference is largely accounted for by the size of the heart, which is typically smaller in females than males. The smaller female heart, pumping less blood with each beat, needs to beat at a faster rate to match the larger male heart's output.
The human heart is a four-chambered pump consisting of two blood-receiving chambers, the right and left atria, and two blood-pumping chambers, the right and left ventricles. With each beat of the heart, blood is forced from the ventricles into the arteries. Each ventricle is capable of ejecting approximately 70 ml of blood with each beat. The larger male heart has a volume slightly larger than this and the female volume slightly lower.
At rest, human tissues and organs require a constant level of blood flow to deliver life-sustaining oxygen and nutrients. The level of blood flow required for the average adult is approximately 5,000 ml per minute. With an ejection volume of about 70 ml, the ventricles need to beat just over 70 times per minute, ejecting 70 ml with each beat, in order to achieve a flow rate of 5,000 ml per minute.
The Faster Female Heart Rate
Simple mathematics tells us that if a heart ejects 70 ml of blood with each beat and beats 70 times each minute, the total blood outflow, or cardiac output, will equal approximately 5,000 ml per minute (70 x 70 = 4,900). A heart that is larger and capable of ejecting 75 ml with each beat will need to beat only 67 times each minute to deliver 5,000 ml of blood. For the smaller female heart ejecting 63 ml blood with each beat, the heart requires approximately 79 beats each minute to achieve 5,000 ml.
The Female Athlete's Heart
Well-trained athletes are known to have slower heart rates than non-athletes. The heart, as a muscle, improves its strength as a result of exercise training, particularly with aerobic training. While the heart rate in female athletes and regular exercisers might therefore be lower than that of an untrained male, it will still beat at a faster rate than an equally trained male athlete or regular exerciser.
The Heart Pacemaker
Heart rate is controlled by a small patch of specialized heart cells located in the right atrium and referred to as the sino-atrial node. This natural pacemaker raises or lowers the heart rate based on information from nerves that respond to body temperature, joint movement, and the levels of oxygen and carbon dioxide in the blood. The female pacemaker, while programmed to function at a higher rate, responds in the same manner to nerve signals as the male heart pacemaker.