Study results highlighted in a news story from a monthly newsletter released by the National Institutes of Health (NIH), indicate that building bone as a young adult can provide life-long benefits. Additionally, the results suggest engaging in physical activity during the aging process can ultimately help maintain bone strength.
See the study abstract here
The news story notes that previous studies encompassing animals suggest that exercise during periods of rapid growth can lead to lifelong benefits in bone size and strength. In an effort to confirm if the same applied to humans, a team of NIH-funded scientists studied more than 100 professional baseball players at different stages in their careers. Since baseball players tend to retire from throwing activities after they have stopped professional play, the scientists were able to look at the impact of physical activity long after intense throwing had ended.
The researchers report that the upper bones in the throwing arms of players were nearly twice as strong as bones in the non-throwing arms. Throwing arm bones exhibited about 50% greater mass, size (total cross-sectional area), and thickness.
The researchers add that while the bone mass benefits from growing were gradually lost as the player aged, about half the bone size benefits and one-third of the bone strength benefits were maintained lifelong. Players who continued throwing during aging lost less bone and kept even more of the strength benefits.