A simple way to test the effectiveness of your exercise program is to find out how well it is training your heart. This is done by measuring your recovery pulse -- how much your pulse slows down in one minute after you stop exercising.A quick recovery signifies a strong heart. The stronger the heart, the more quickly it recovers from stress and the less frequently it must beat. If you are reasonably fit, you can test yourself periodically to chart your improvement. Work out as hard as you can for five minutes. Stop and immediately place one or two fingers at the side of your neck where you can feel a strong pulse. Count your pulse for six seconds, then multiply that number by 10. It is important to count for only six seconds, since your heart rate decreases very quickly once you stop exercising. Exactly one minute later, take your pulse again in the same way. Then subtract the second pulse rate from the first. The difference between the two rates is your Recovery Pulse Index. You are in good shape if the second count is at least 30 beats lower than the first, and you should be able to increase the difference as your heart gets stronger. If you think that your slow heart rate is a measure of fitness, you could be wrong. Your recovery heart rate is a far more dependable indicator. A study in Medicine and Science in Sports and Exercise shows that a 20-week program of endurance training does not slow the resting heart rate, and therefore cannot be use as a measure of fitness. Hard exercise cannot hurt a healthy heart, but it can cause irregular heart beats in people who have damaged hearts.