For many years doctors, practitioners of exercise as well as parents discourage their children from pre-pubertal weight training and resistance. The old school approach argued that weight training would slow or stop the skeletal development of children. Modern research has dissolved all previous concerns and come to support new data.
According to Wayne Wescott, Ph.D. (Specialized Strength Training, 2001) with progressive resistance training is really the best way to enhance musculoskeletal development of boys and girls. Other studies have even shown that training with resistance has the greatest positive effect on bone formation during the prepubertal (bass, 2000). This potential benefit may be especially important for young women who are at increased risk of osteoporosis