Start Early to Reap the Benefits of Physical Activity

Whereas it is established that exercise causes muscles to grow bigger and leaner, data now suggests that routine physical activity may offer similar benefits for bones as well. S. Warden, from the Center for Translational Musculoskeletal Research and Department of Physical Therapy at Indiana University (Indiana, USA), and colleagues assessed 103 professional baseball players to ascertain insights as to the impact of exercise on bones.  The researchers found that the ball players had up to twice the bone strength in their throwing arms (humeral diaphysis bone) as in their non-throwing arm—as measured by bone size and density.  Once their careers ended, some players continued an active lifestyle, while others did not. Bone mass in those that stopped throwing reverted back to matching the other arm, but bone size did not (dropping to just 56% of its previous size on average), which meant that even in the absence of continued activity, the players all maintained some bone strength attributes for the rest of their lives. For those that continued to use their arms after retiring from baseball the benefits were even greater—they maintained higher bone density levels, though not as high as when they were playing of course (28% on average), which resulted in them retaining up to 50% of added bone strength as they aged into becoming senior citizens. The study authors submit that: “physical activity during youth should be encouraged for lifelong bone health, with the focus being optimization of bone size and strength rather than the current paradigm of increasing mass. The data also indicate that physical activity should be encouraged during aging to reduce skeletal structural decay.”