Aug. 25, 2004 -- All those flips and vaults can really wear down elite gymnasts -- literally, according to two new Greek studies.
If you've been following the Olympic gymnastic competitions in Athens, it should come as no surprise that the world's best gymnasts tend to be shorter and lighter than other people their age.
The reason may be because they train so hard, so long, for so many years.
Top-notch competitors often start gymnastics when they're barely out of diapers. Girls do their most intense training in the years around puberty; boys max out their training toward the end of puberty.
That's a critical time for growth and bone development.
For anyone -- athlete or not -- growth depends on a combination of genetic and environmental factors. Stress, exercise, and nutrition can all influence development, and sex hormones like estrogen and testosterone affect maturation.
To find out how world-class training affects gymnasts' bodies, scientists from the University of Patras Medical School in Patras, Greece, studied 262 male and female gymnasts competing at the 2002 European Championship of Artistic Gymnasts.
The gymnasts, all of whom were white, were aged 13 to 23. They were weighed, measured, and had their bone mass and skeletal maturation checked.
Both sexes were "shorter and thinner than their age-related counterparts, and they showed a significant delay in skeletal maturation," write the authors of a study led by Neoklis Georgopoulos.
The differences were much greater among the female gymnasts. That might mean that "females are more vulnerable than males to the detrimental effects of stress and intensive physical training on growth," write the researchers.
Or it could just mean that short-limbed girls tend to make good gymnasts, say the authors.
Male and female gymnasts also showed a delay in bone age, according to a study led by Kostas Markou.
Again, the female athletes had the greater difference. Their bones were developing about two years behind their actual age; the males had a one-year gap.
"The earlier the age of onset of exercise, the worse the effect on bone acquisition" in female gymnasts, writes Markou's team.
Those delays in growth and bone development can be overcome in time.
In fact, female athletes might eventually beat their non-gymnast peers at bone acquisition, thanks to years of bone-building, weight-bearing exercise.
Meanwhile, now you know why there aren't many NBA-sized elite gymnasts flipping their way along balance beams.