Answer
The transport of oxygen in the human body is adaptable. It reflects the needs of the body due to its own activities and the external availability of oxygen. These athletes are altering the availability of oxygen around their planned activities to insure they have ample access to oxygen within muscle tissues during the event.
Work Step by Step
The athletes competing at sea level are encouraging their bodies to adapt to less available oxygen so that, during their actual competition in a more oxygen-rich environment, they are theoretically making better use of available oxygen and providing even better support to tissues. The mountain climbers are making sure they have access to ample oxygen in an environment that is oxygen poor.
