Researchers find physical activity in youth leads to stronger bones in old age

March 25, 2014 by Bob Yirka report
Reconstructed CT images of the humerii of a professional baseball player reveal a bigger bone in the throwing arm than on the non-throwing arm when the bone is viewed from the front (left images). Cross-sectional images (right) displayed greater total and cortical bone areas, greater cortical thickness, and smaller medullary area in the throwing arm than in the non-throwing arm. The net result was a stronger bone in the throwing arm, with one-third of the bone strength benefit lasting lifelong in retired players despite throwing being completed more than 50 years earlier. Credit: Stuart Warden

(Medical Xpress)—A team of researchers with members from the U.S. and Australia has found that people who exercise when young tend to increase the size and strength of their bones, which appears to make for lifelong benefits. In their paper published in Proceedings of the National Academy of Sciences, the team describes how they studied the bones in the arms of professional baseball players over the course of their lives and how their activities impacted bone size and strength.

Everyone knows that exercise causes muscles to grow bigger and leaner, now it appears it offers similar benefits for bones as well. In this new study, the research team enlisted the assistance of 103 professional baseball to learn more about the impact of exercise on bones.

In their study, the researchers found that the ball players had up to twice the 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 percent 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 percent on average), which resulted in them retaining up to 50 percent of added bone strength as they aged into becoming senior citizens.

The results of this study indicate that exercise during youth is perhaps even more important than has been previously thought. People breaking bones in their declining years is very common, if today's young people could be coaxed into exercising enough to increase the size and density of their bones, it appears likely they will be less susceptible to breakage when they grow older.

Explore further: Researchers stress weight-bearing exercise for bone strength

More information: Physical activity when young provides lifelong benefits to cortical bone size and strength in men, Stuart J. Warden, PNAS, DOI: 10.1073/pnas.1321605111

Abstract
The skeleton shows greatest plasticity to physical activity-related mechanical loads during youth but is more at risk for failure during aging. Do the skeletal benefits of physical activity during youth persist with aging? To address this question, we used a uniquely controlled cross-sectional study design in which we compared the throwing-to-nonthrowing arm differences in humeral diaphysis bone properties in professional baseball players at different stages of their careers (n = 103) with dominant-to-nondominant arm differences in controls (n = 94). Throwing-related physical activity introduced extreme loading to the humeral diaphysis and nearly doubled its strength. Once throwing activities ceased, the cortical bone mass, area, and thickness benefits of physical activity during youth were gradually lost because of greater medullary expansion and cortical trabecularization. However, half of the bone size (total cross-sectional area) and one-third of the bone strength (polar moment of inertia) benefits of throwing-related physical activity during youth were maintained lifelong. In players who continued throwing during aging, some cortical bone mass and more strength benefits of the physical activity during youth were maintained as a result of less medullary expansion and cortical trabecularization. These data indicate that the old adage of "use it or lose it" is not entirely applicable to the skeleton and 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.

Related Stories

Researchers stress weight-bearing exercise for bone strength

March 17, 2014
When Denise Allee went shopping at Terre Haute's Honey Creek Mall on a recent Saturday, she left with some piece of mind.

Exercise in early 20s may lower risk of osteoporosis

February 13, 2012
Physical exercise in the early twenties improves bone development and may reduce the risk of fractures later in life, reveals a study of more than 800 Swedish men carried out at the Sahlgrenska Academy at the University of ...

Keep on exercising, researchers advise older breast cancer survivors

December 9, 2013
To build and maintain muscle strength, it is best for older breast cancer survivors to follow an ongoing exercise program of resistance and impact training. This advice comes from Jessica Dobek of the Oregon Health and Science ...

'Force strength' could indicate bone health in ballet dancers

January 20, 2014
Ballet dancers' bone health is under investigation in an attempt to understand the long associated risk of bone stress injury—responsible for shattering the careers of many talented performers.

NASA study provides new findings on protecting astronauts' bones through diet and exercise

August 24, 2012
(Phys.org)—Eating the right diet and exercising hard in space helps protect International Space Station astronauts' bones, a finding that may help solve one of the key problems facing future explorers heading beyond low ...

Recommended for you

High-fat diet in pregnancy can cause mental health problems in offspring

July 21, 2017
A high-fat diet not only creates health problems for expectant mothers, but new research in an animal model suggests it alters the development of the brain and endocrine system of their offspring and has a long-term impact ...

To combat teen smoking, health experts recommend R ratings for movies that depict tobacco use

July 21, 2017
Public health experts have an unusual suggestion for reducing teen smoking: Give just about any movie that depicts tobacco use an automatic R rating.

Why sugary drinks and protein-rich meals don't go well together

July 20, 2017
Having a sugar-sweetened drink with a high-protein meal may negatively affect energy balance, alter food preferences and cause the body to store more fat, according to a study published in the open access journal BMC Nutrition.

Opioids and obesity, not 'despair deaths,' raising mortality rates for white Americans

July 20, 2017
Drug-related deaths among middle-aged white men increased more than 25-fold between 1980 and 2014, with the bulk of that spike occurring since the mid-1990s when addictive prescription opioids became broadly available, according ...

Aging Americans enjoy longer life, better health when avoiding three risky behaviors

July 20, 2017
We've heard it before from our doctors and other health experts: Keep your weight down, don't smoke and cut back on the alcohol if you want to live longer.

Parents have critical role in preventing teen drinking

July 20, 2017
Fewer teenagers are drinking alcohol but more needs to be done to curb the drinking habits of Australian school students, based on the findings of the latest study by Adelaide researchers.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.