Fitness Age
The picture that you are seeing is a TomTom Spark 2. The reason why I post it, is because and awesome stat that it gives you. That stat is fitness age! My biological age is 36, but after running for a few months, increasing the heart rate as long as the gadget request it. Now my fitness age is of 20 and my ability to run as gotten a lot better. I will give more details tomorrow.