Determines personal heart rate limits for a training session. The Polar OwnZone (OZ) feature determines an individual training zone. It guides you through an appropriate warm-up routine and automatically determines a safe and effective training heart rate zone - your OwnZone - while taking into account your current physical condition. Polar Heart Rate Monitors use multiple methods for determining your OwnZone. The primary method is to measure your heart rate variability during the warm-up period before training. If the measurement is not successful, your latest saved OwnZone limits are used. If there are no previous limits in the memory, the Polar Heart Rate Monitor will automatically calculate OwnZone limits based on your age-predicted maximum heart rate (220 minus age). You should determine your OwnZone at the beginning of your workout whenever you change training environment and/or training mode or if you feel stressed, or not recovered. The OwnZone Basic corresponds to 65-85 % of the maximum heart rate. Training at the lower end of this intensity level can be conducted for extended periods safely and often yields the best results for weight control, while workout at the upper end of this intensity produces the best results for improving aerobic (cardiovascular) fitness. The OwnZone Advanced feature consists of two training areas: OwnZone Low and OwnZone High, providing greater variations in training than the OwnZone Basic area, which can be rather wide for more focused training. The OwnZone Light corresponds to 60-70% of your maximum heart rate. This intensity feels fairly easy for most people. It helps in weight control and improves endurance and cardiovascular fitness. The OwnZone Moderate corresponds to 70-80% of your maximum heart rate. This intensity is especially good for people who are training regularly. Training in this zone is particularly effective for improving cardiovascular fitness. The OwnZone Hard corresponds to 80-90% of maximum heart rate. You will find yourself breathing heavily, having tired muscles and feeling fatigued. This intensity is recommended occasionally for fit people.