I don't understand the reason to follow or be followed what does it change? Does it change the profile or what someone please explain? All I know is on my old profile I started getting some and it made me feel good about myself but I didn't know what the actual thing was for? But now I have 0 so after explaining to me what's for follow me and I'll return the favor.
I think it's for motivation. So you can see what type of workouts they do if you like the results they are getting. That's my guess anyways.
As the previous posted stated the purpose is motivation and inspiration. Pushing each other to get the best out of each other. They are paying attention to your workout schedule. Have alot of followers from different places and cheer them on each time.