Exercise Stress Testing Standard ETT (Exercise Tolerance Test) Exercise testing is used to evaluate the heart and lung function of children. This is especially important in children with heart muscle damage or injury, complex structural heart problems, and rhythm (heartbeat) problems. Our pediatric exercise laboratory uses a stationary bicycle or a treadmill. Patches are placed on the patient's chest and connected to wires from a heart monitor. The patient's heart rate, rhythm, and blood pressure will be checked at rest, during exercise and after exercise. The patient walks/runs on a treadmill or rides the bike until he/she can no longer walk/run or pedal any further—a maximal effort. The entire test from beginning to end takes about 1½ hours to complete. Metabolic ETT An Exercise Tolerance Test as described above, but in addition, the patient breathes through a special mouthpiece to determine how much and how effectively the body uses oxygen. The test is done on either the treadmill or bicycle. Preparation Instructions for Exercise Testing Eat a light meal before coming, wear comfortable clothes, shorts or sweat pants and sneakers.