Spotting heart attacks--beforehand.

The article reports that according to a study by physician of the U.S. National Aeronautics & Space Administration (NASA), Robert L. Fleck, exercise not only helps the healthy but can also spot the man who is in danger of heart attack. He says that after hard exercise about 2% of the men had abnormal electrocardiograms. NASA's experiment involved 40 men at a high executive level.