The FitnessGram PACER Test is a multistage aerobic capacity test that progressively gets more difficult as it continues. The test is used to measure a student's aerobic capacity as part of the FitnessGram assessment. Students run back and forth as many times as they can, each lap signaled by a beep sound. Remember to run in a straight line, and run as long as possible. The second time you fail to complete a lap before the sound, your test is over.