Heart rate is important to monitor while you exercise because it is an indication of intensity and calories burned. While working out, you should aim for a heart rate (measured in beats per minute) to be at a level that is effective and corresponds with your fitness/weight loss goals. It is also important to stay in a zone that is safe.
If your heart rate is too low, you may not get the results you want. If it’s too high, you may not maximize fat burning potential, or even worse, you could be exercising at an unsafe intensity.