This can be interpreted a bunch of different ways! Fitness comes in many different packages. This can be about characters who are super fast, strong, agile, good at dancing, good at climbing, athletes, or foodies! Whatever it means to you. This is inspired by those routines you see in magazines for actors, but with more of an open mind and less body shaming.
Some of the training or skills on this list are not physical but I didn’t want to make list of only fighting skills, so there’s a wide range of skills from mind powers, creativity, and other deadly skills.