The Polar Fitness Test is an easy, safe and quick way to estimate your aerobic fitness at rest. The result, “Polar OwnIndex”, is comparable to maximal oxygen uptake, which is commonly used to evaluate aerobic fitness. The better your aerobic fitness, the stronger and more efficient your heart is. Your long-term training background, heart rate, heart rate variability at rest, gender, age, height, and body weight all influence OwnIndex. Before starting the test, make sure your physical settings including training background are accurate. You can check and change the settings in the Polar Flow web service under in “Settings”>“Physical settings” or from the Polar Flow app under your profile picture. If you make any changes, sync M430 with the web service or app, before you start the fitness test. The Fitness test is fully automatic and you can perform it at rest in less than five minutes with your wrist-based heart rate device. To perform the fitness test, go to “Fitness Test” on the menu, lie down and relax for 1-3 minutes before starting the test. Start the test by pressing the “start”-button when you are ready. The test will start when your heart rate is found. Stay relaxed and limit your body movements and communication with other people. When the test is over your M430 vibrates twice and you get a description of your fitness test result and your estimated VO2max is displayed. You can update your VO2max value as the latest results by choosing “YES” to the update question. Your latest test result is shown in “Latest result” under “Fitness test” menu. Only your most recently performed test result is shown there. You can see all previous fitness test results from the Flow mobile app and Polar web service.