Running Loose deals with serious problems—parent/child relationships, dating, sex, racism and death—with a light-hearted tone. The novel also explores whether athletics in high school is taken too seriously.

Louie Banks starts his senior year with high hopes of having a successful football season, graduating, and getting into college. The year begins well. He is in excellent physical shape due to hard work, and the football team is off to another winning record. (Sports fans will enjoy the many references to football tactics and plays.) A smart, pretty cheerleader decides she likes him, so he has a terrific personal relationship going. But trouble begins when the coach insinuates that the black quarterback for their toughest opponent should be put "out of the game! Early!" When the deed is actually done, Louie's ideals of sportsmanship won't allow him to play any more, and he embarrasses the coach by making a scene and walking off the field. How Louie copes with this decision makes up much of the book, and the issues are not clear cut. Louie's best friend Carter, for example, is able to continue playing, justifying his compliance in ways that make Louie's stand against injustice seem pointless. However, the coach and the school principal are evil types, so Louie's civil disobedience seems admirable.

Louie's physical relationship with the more experienced Becky is sensitively portrayed. The characters' attitudes toward sex and the choice to wait are positive and responsible messages for young readers.

When Becky dies suddenly, Louie's life is even more stressed and confusing. His behavior shocks the town but seems understandable to the reader who feels the sadness with Louie.

Despite the many unsettling events, Crutcher tells the story with a consistent tone of humor and sympathy. Louie never fails to see the ridiculous side to his own behavior and to make fun of himself. He also gets plenty of amusing jabs in against the people around him whom he does not respect. Louie is an endearing character, and the reader feels empathy for him throughout the novel.