It's nice to have metrics to measure your progress with an exercise routine (walking, running, strength training), weight loss effort (lbs lost, fat %), etc. Although there are always narcissists, I think many people just like quantifying their progress. Just like receiving grades to measure your understanding when you were in school, these metrics allow you to assess whether you are moving in the right direction, and if so, to feel a sense of accomplishment. Wanting to be fit and healthy does not equal narcissism.