As you run, the performance condition feature analyzes your pace, heart rate, and heart rate variability to make a real-time assessment of your ability to perform compared to your average fitness level. During the first 6 to 20 minutes of your run, the watch displays your performance condition score. For example, a score of +5 means that you are rested, fresh, and capable of a good run. You can add performance condition as a data field to one of your training screens to monitor your ability throughout the run. Performance condition can also be an indicator of fatigue level, especially at the end of a long training run.