Peak bone mass (PBM) is a negative predictor of osteoporosis and lifelong fracture risk. Because osteoporosis is such a prevalent disease with life-threatening consequences, it is important to try to maximize PBM. Adolescence is a critical period for bone acquisition. This article discusses some of the differences in male and female skeletal development and modifiable factors that enhance bone accrual in this age group, particularly in athletes. Hormonal influences, effects of physical activity, and nutritional contributions are included, with a focus on the adolescent athlete. Emphasis is placed on the importance of appropriate energy availability in this age group. We also review prevention and treatment strategies for the female athlete triad (ie, the inter-relationship of decreased energy availability, menstrual irregularity, and low bone density) in adolescents and athletic women. Recommendations for maximizing bone density in both male and female adolescents are discussed.