A heart rate variability (HRV) test is used to help assess your nervous system. The nervous system creates proper heart function and ultimately leads to good health. During the test, you will wear a heart rate monitor that will record fluctuations and variations of your heart rate. HRV is a non-invasive way to measure the adaptability of your nervous system to handle stress as well as your level of physical fitness. The device is from the United States, unlicensed in Canada and is used for investigative research; the requisite Health Canada approvals are not in place.