Taken from Dr. George H. Malkmus, “Why Christians get sick”, The human body, depending on size, has approximately five quarts of blood which are constantly traveling
through the entire body, making 3,000 to 5,000 round trips a day! The heart pumps some 20,000,000,000 (20 billion) blood cells throughout the body. These blood cells carry nourishment to the body cells, while collecting wastes to be removed from the body.
The heart muscle must be kept strong in order to keep the blood continuously moving with good strength as it feeds and cleanses the body cells. Many people fail to realize the absolute necessity of aerobic exercises for the maintaining of a strong heart to pump the blood.