Most people know that you have to warm up skeletal muscles to help protect them from injury, but many do not know that warming up the heart muscle also helps to prevent heart attacks in people with blocked arteries leading to the heart.
Before you try to run very fast, you can protect your muscles from injury by performing a series of runs of gradually-increasing intensity to increase the circulation of blood to your muscles. The same principle applies to the heart. Angina is a condition in which the blood vessels leading to the heart are partially blocked so the person has no pain at rest, but during exercise, the blocked arteries don't permit enough blood to get through to the heart muscles, causing pain. A study from the Quebec Heart Institute shows that exercising very slowly before a person with angina picks up the pace allows him to exercise more intensely before he feels heart pain.