This investigation ascertained effects of exposing high school students to classroom health-related fitness instruction involving a curriculum focused on the relationship of exercise to cardiorespiratory fitness, body composition, flexibility, strength (particularly as it relates to abdominal and lower-back muscoskeletal function), and muscular endurance. The curriculum included lectures, labs, and readings as part of the physical education course work. Ninety ninth and 10th grade students were assigned randomly to one of three physical education classes, which met daily for one, 12-week semester. Each class received the same skill-related instruction; however, the two experimental classes, in lieu of skill activities, were exposed to classroom instruction and readings dealing with health fitness topics on a one or two day per week basis. The third class of students, the control group, was engaged strictly in skill activities daily. Students exposed to health-related fitness classroom instruction displayed significantly more positive attitudes toward physical activity and a better understanding of health-related fitness than students who did not receive such information.