Anyone who has had a stress test knows that stress tests are not easy and can even be painful! The commonly-used Bruce protocol for treadmill exercise tests includes 7 stages of 3 minutes each. The first stage starts at a 10% grade at a speed of 1.7 miles per hour. Each stage increases by 2% and between 5-9 miles per hour. Even though a stress test can last for over 20 minutes, most people don't last longer than seven minutes on the treadmill. However, it is important to keep going as long as possible to collect lots of data and be sure to reach the target heart rate. Each additional minute of a stress test could yield important information about the heart's condition.