The resting heart rate in adults is usually 60 to 100 beats per minute, and in normal people it fluctuates within the normal range throughout the day.
The heart rate is neat and regular, there will be no arrhythmia, and occasionally there will be atrial preterm contraction, mostly functional, which is a normal phenomenon. The pattern of change is high during the day and low at night, high during exercise and low during rest.
This is because during the day in the activity state, sympathetic nerve tone increases, heart rate increases, while at night to rest, sleep, vagus nerve tone increases, heart rate slows down.
In addition, people who exercise regularly have a slower average heart rate, for example, athletes often have a heart rate below 60 beats per minute, while people with less daily activity have a faster average heart rate.