You could try following one of the pros, they may be open to being followed; however if you want to look at personal stats it would only be polite to make such a request openly once you’ve been able to follow. 

My 2c - the fitness score grows with higher-than-usual effort. That means that for regular people, it may jump up quite a bit after a long run or ride. However for professional athletes, I’d rather expect a more balanced performance - meaning that their fitness score will slightly fluctuate but will be more or less the same for longer periods of time.