Increasing numbers of studies in sports science have been examining the value
of high altitude training for endurance athletes and more countries are
establishing special high altitude training facilities. All of this has
focused on the following hypotheses:
1. People living at altitude have more hemoglobin than do people who live
at sea level.
2. People living at altitude similar hemoglobin levels as their low-living
counterparts, but a greater percentage of the haemoglobin binds to oxygen
molecules in the blood.
Recent research now suggests that yet another mechanism may be involved
because it has been found that residents of a high-altitude village in
Ethiopia, most surprisingly, not only have only have haemoglobin levels
similar to those seen in sea level populations but they also display similar
rates of binding between oxygen and haemoglobin. It would thus appear that
one can be high altitude adapted and still display the same physiological
characteristics as those living at sea level.
This will be research that is well worth keeping one's eye upon, especially
with regard to its implications for methods of endurance training. Until
recently it was the "secrets" of the Kenyan distance runners; now we are
being compelled to see what secrets lurk in a nondescript little mountain
village in the highlands of Ethiopia.
Semper aliquid novi ex Africa (always something new from Africa)!
Read more about this research in the latest Scientific American:
<http://www.sciam.com/article.cfm?chanID=sa003&articleID=0007CA17-DF07-1DEB-A8
38809EC588F2D7>
Scientists Discover New Adaptation to Oxygen-Poor Air at High Altitudes
Visitors to high-elevation locales often experience difficulty breathing
because the amount of oxygen available in the atmosphere decreases with
increasing altitude. In extreme situations, altitude sickness can be fatal.
But people born and raised at high altitudes function well despite the
reduced availability of oxygen. New findings published online this week by
the Proceedings of the National Academy of Sciences, suggest that
residents of a high-altitude village in Ethiopia have a unique way of
adapting to the lower levels of oxygen at high elevations.
Previous research had suggested two ways that humans may adjust to lower
oxygen levels. Both methods involve hemoglobin, a protein in red blood
cells that binds to oxygen and carries it throughout the body. Members of a
well-studied group living the Andes, for example, have more hemoglobin than
do people who live at sea level. Natives of the Tibetan plateau, in
contrast, have similar hemoglobin levels as their low-living counterparts,
but a greater percentage of the protein binds to oxygen molecules in the
blood.
Cynthia M. Beall of Case Western Reserve University and her colleagues
studied 313 native residents of the Ambaras Region of the Semien Mountains
National Park in Ethiopia, situated 3,530 meters above sea level.
Surprisingly, the subjects not only had hemoglobin levels similar to those
seen in sea level populations but they also displayed comparable rates of
binding between oxygen and hemoglobin.
The authors posit that the Ethiopian population represents a third method of
adaptation to high-altitude oxygen deprivation, although the underlying
biological mechanisms remain unknown. Learning why the three populations
differ, they conclude, will require further investigation....
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Dr Mel C Siff
Denver, USA
http://groups.yahoo.com/group/Supertraining/
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