Jack Ballard has problems. He suffers from a sense of inferiority to his bright and athletic older brother and sister. Once a 97-pound weakling, at the opening of the story, Jack has developed his muscles but doesn't know what to do with them. The 16-year-old's family moves to California, where Jack tells his new schoolmates he has been a star athlete and scholar. Then he has to try to live up to his part. With Coach Jade's encouragement and some hard work, he succeeds in breaking the pole vault record. The accompanying romantic problems work out when Jack turns from the local glamour pot to the friendly, loyal girl who has loved him all the time. The physical fitness theme suggested by the title is glossed over. The book flows slickly, but the language is often archaic or asinine, and the characters are thoroughly stereotyped.