Summarize Bone Health: Powerpoint
Bone Health. Despite traditional fears that resistance training would be harmful to the immature skeletal of youth, current observations suggest that childhood and adolescence may be the opportune time for the bone modeling and remodeling process to respond to the tensile and compressive forces associated with weight-bearing activities (15,121,230,235). Indeed, weight-bearing physical activity is essential for normal bone formation and growth (148). If age-specific resistance training guidelines are followed and if nutritional recommendations (e.g., adequate calcium) are adhered to, regular participation in a resistance training program can maximize bone mineral density during childhood and adoles- cence (230,235,238). Moreover, there is no detrimental effect of resistance training on linear growth in children and adolescents (91,147) Results from several research studies indicate that regular participation in sports and specialized fitness programs that include resistance training can be a potent osteogenic stimulus in youth (16,20,50,145,154,166,173,237,241). It has been reported that adolescent weightlifters displayed levels of bone mineral density (50) and bone mineral content (237) well above values of age-matched controls. Other researchers found that weightlifting can impart some benefit on bone development in youth but not as much as year-round soccer (20). The repetitive exposure to physical loading in sports such as gymnastics has also resulted in significantly higher bone mineral density in young athletes as compared with age-matched controls (16,241). In a study that provides direct evidence that high-impact exercise enhances bone accrual in preadolescent girls, participation in a 10-month physical activity program (combined resistance training and aerobic exercise) resulted in significant improvements in bone mineral density in the exercise group as compared with the control group (166). Likewise, preadolescent boys who performed a high-impact circuit exercise program for 20 months had greater bone expansion on both the periosteal and endosteal surfaces (145). Others noted that a school-based physical activity intervention that included plyometric training enhanced bone
mass at the weight-bearing proximal femur in children (154). Although peak bone mass is influenced by genetics (43), regular participation in high-strain-eliciting sports and specialized exercise such as resistance training may have a desirable influence on bone health in children and adoles- cents. It appears that the osteogenic response to exercise in youth can be enhanced by sensibly prescribing multi-joint, moderate to high intensity resistance training exercises (e.g., bench press, squat, and weightlifting movements) and unaccustomed plyometric exercises (e.g., jumping and hopping). Although additional clinical trials are needed to more precisely define the exercise prescription, the impor- tance of maintaining participation in sports and specialized activities throughout life must not be overlooked because training-induced improvements in bone health may be lost over time if the program is not continued (110).