Women’s hearts beat faster then men’s. The main reason for this is simply that on average women tend to be smaller then men and have less mass to pump blood to.

An average man’s heart weighs 10 ounces, and a woman’s heart weighs only 8 ounces. Women’s hearts make up for their smaller size by beating a little faster. The average heart rate of a man is 70 beats/minute, and that of a woman is 78 beats/minute according to ABC News