<span>A. Training Intensity, Heart Rate Reserve or HRR is used to describe the difference between resting heart rate and maximum heart rate. Monitoring our heart rate is important especially to the people who are looking for weight loss and fitness improvement and it is also indicates the heart rate reserve cardiovascular fitness of a person. The more people become fitness the more their heart become more efficient at pumping blood to the rest of the body.</span>
2.6 million years ago. I hope that helps!
