What is the relationship between heart rate and exercise?

The relationship between heart rate and exercise is characterized by the fact that heart rate increases with exercise intensity. As physical activity begins and becomes more vigorous, the body demands more oxygen and nutrients to fuel the muscles. To meet this increased demand, the heart pumps more blood, resulting in a higher heart rate.

During low-intensity exercise, the heart rate will rise, but not as significantly as it would during high-intensity activities. This increase in heart rate serves to enhance the delivery of oxygen and the removal of carbon dioxide from the working muscles. Monitoring heart rate is a critical aspect of exercise training, as it helps individuals gauge their exercise intensity and ensure they are working within their desired training zone.

The other options do not accurately depict this physiological response. For instance, heart rate does not remain constant during exercise; rather, it fluctuates in accordance with physical demands. It also does not decrease during exercise, nor is it unrelated to exercise intensity, as there is a clear and direct correlation. Understanding this relationship is essential for effective fitness training and improving cardiovascular health.