What is "My Best Performance"

Problem: The diary displays My Best Performance. But that was not my fastest performance. What is it then?
Explanation: My Best Performance is based on the fitness value you achieved. The theory behind that is your most economic run — not necessarily your fastest.
On Fitness: In TrailRunner, the fitness is a calculated value based on the average pace and heart rate of a workout. The idea is that if you where very fast with a low heart rate you are fitter, while the opposite applies if you where very slow and had a high heart rate. This value is just for orientation and does not have the accuracy of the methods used in Polar watches or other biometric methods, but it gives a pretty good overall impression. To compare your fitness values to average adults, take a look into this table.