I'm comparing to other fitness activities. Sure, you can have going to the gym as a hobby, but it's generally harder than biking, swimming, climbing, martial ar

I'm comparing to other fitness activities. Sure, you can have going to the gym as a hobby, but it's generally harder than biking, swimming, climbing, martial arts, team sports or other things that offer additional value of more visible progression, social interaction, making friends, traveling to new places etc.