What are heart murmurs in children? Heart murmurs are extra or abnormal sounds made by turbulent blood flowing through the heart. Murmurs are graded on a scale of 1 to 6, based on how loud they are.
The heart rate level to burn fat will depend on your age, diet, and fitness, typically falling between 64% to 76% of your maximum heart rate. For example, a 40-year-old swimmer should try to keep ...