Increasing exercise in children and adolescents through academic classes is an understudied area. Potential benefits include associated improvements in health, psychosocial, and quality-of-life factors. A sample of 98 students (M(age) = 14.3) from high school health education classes received six, 40-min lessons incorporating cognitive-behavioral methods to increase exercise over 6 weeks. Significant within-group improvements in exercise, mood, and body satisfaction were found, with slightly larger effect sizes identified for the boys. Increase in exercise was significantly associated with reduced mood distress (β = -.17, p < .001). For the girls only, change in body satisfaction significantly mediated that relationship, and a reciprocal relationship between changes in mood and body satisfaction was also identified. Incorporation of lessons emphasizing goal setting and self-regulation within high school health education classes may foster increased exercise and associated improvements in mood and body satisfaction. For girls, the positive effects may reinforce one another.