A stress test, helps your doctor to find out how well your heart handles its work load. An exercise stress test usually involves walking on a treadmill while your heart rhythm, blood pressure and breathing are monitored. Your doctor may recommend an exercise stress tests if he suspects you have coronary disease or an irregular heart rhythm. It gathers information about how your heart works during physical activity, because exercise makes your heart pump harder and faster than usual , an exercise stress test can reveal problems within your heart that might not be noticeable otherwise. You may be asked not to eat , drink or smoke for two hours or more before the test .Ask your doctor if you should avoid caffeine or certain medication the day before the test as they interfere with certain stress tests. You should wear loose clothes and walking shoes. Shorts, sweatpants and jogging shoes are good choices.