This document discusses cardiovascular diseases, specifically coronary artery disease (CAD). It defines CAD as a condition where the coronary arteries become damaged or diseased due to plaque buildup. Common signs and symptoms of CAD include angina, rapid heartbeat, and shortness of breath. The document provides guidelines for exercise for those with CAD, stating it should be low intensity cardiovascular exercise for 20-30 minutes 3-5 days per week, and noting beneficial exercises include stationary cycling and treadmill walking while contraindicated exercises involve heavy lifting or high intensity activity.