Answer:
Step-by-step explanation:
A very fit person might have a slower heart rate than someone of average fitness for several reasons:
Increased cardiac efficiency: Regular exercise and physical activity can improve the efficiency of the cardiovascular system, including the heart. This means that the heart can pump more blood with each beat, allowing it to do the same amount of work with fewer beats. As a result, a fit person's heart can maintain an adequate blood supply with a slower heart rate.
Greater stroke volume: Stroke volume is the amount of blood that is pumped out of the heart with each beat. With regular exercise, the heart muscle becomes stronger and can pump more blood with each beat. As a result, the heart can maintain an adequate blood supply to the body with fewer beats.
Increased parasympathetic tone: The autonomic nervous system controls heart rate. The parasympathetic nervous system is responsible for slowing down heart rate. Regular exercise can increase the activity of the parasympathetic nervous system, which can lead to a slower heart rate.
Lower sympathetic tone: The sympathetic nervous system is responsible for increasing heart rate in response to stress or exercise. Regular exercise can lower the activity of the sympathetic nervous system, which can lead to a slower heart rate.
Overall, a very fit person may have a slower heart rate than someone of average fitness due to improved cardiac efficiency, greater stroke volume, increased parasympathetic tone, and lower sympathetic tone.