A stress test, also called an exercise stress test, 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.An exercise stress test usually involves walking on a treadmill or riding a stationary bike while your heart rhythm, blood pressure and breathing are monitored.Your doctor may recommend an exercise stress test if he or she suspects you have coronary artery disease or an irregular heart rhythm (arrhythmia). The test may also be used to guide your treatment if you've already been diagnosed with a heart condition.