Effects of training on bone metabolism in young athletes

Purpose. This study investigated the effects of two types of training on the bone formation marker of osteocalcin and the bone resorption marker of tartrate-resistant acid phosphatase isoenzyme 5b (TRAP5b) in young track and field boys and girls. Methods. The 14-year-old group (10 boys, 10 girls) performed first time an intensive and supervised 8-week plyometric training. In the 17-year-old group (13 athletic boys, 6 control boys, 12 athletic girls, 6 control girls), the normal many-sided track and field training lasted 6 months. Results. Significant increases were noticed in osteocalcin (p < 0.01) both in younger boys and girls. The 20-m sprint performance improved in girls (p < 0.01) and the countermovement jump height increased in boys (p < 0.001). Significant increases in 17-year-old boys and girls were observed after training in osteocalcin (p < 0.01), osteocalcin/TRAP5b ratio (p < 0.01 and p < 0.001), and the standing 5-jump (p < 0.05 and p < 0.01). Serum TRAP5b decreased both in boys (p < 0.05) and in girls (p < 0.01). The boys also improved the standing 5-jump (p < 0.01) and the 12-minute running test results (p < 0.05). In the combined group of all subjects, the correlation coefficient between TRAP5b and age was significant (r = –0.63, p < 0.001, n = 57). Conclusions. In practice, it is important to add plyometrics and other strength training in the training plans of young athletes, regardless of their events, to increase their bone metabolism and muscle strength.