By Todd Chapman, MD, FACS: In 1968, the Olympics were held in
Mexico City, 7,349 feet above sea level. In addition to
popularizing the "Fosbury Flop," (Dick Fosbury’s gold medal
winning backwards high jump) the games were all about high
altitude competition and training. It was clear that Olympic
athletes from countries at low altitude (near sea level) had to
acclimatize to Mexico City’s thinner air if they were to have a
chance. The issue naturally came up at events a few weeks later:
do the altitude-trained athletes have an advantage when they
return to sea level? The most well known adaptation to high
altitude is an increase in the hemoglobin concentration of the
blood. This raises oxygen carrying capacity, so that even with
less oxygen available in the air you breathe, the total oxygen
content of the blood remains normal. Then when you return to sea
level, the oxygen content is abnormally high. The question is,
does this give you an advantage? This has been studied in
animals and humans. There are two fun