As your heart adapts to aerobic activity, it becomes a stronger and more efficient pump. One of the indicators of the efficiency of the heart is resting heart rate. A lower heart rate (generally) means that your heart is more efficient and you are more fit.

Use the norms in the graph in the multimedia slide to estimate your fitness level. Be sure to use your morning resting heart rate. Take your heart rate in the morning when you wake up for 3 or 4 days. Use the average to signify your normal resting heart rate.