The Hypoxia-Enducible Factor

The requirement for an attitude to work is that the carburetor and the engine are adaptable. So your animal returned from altitude potentially with two, three, four, five percent more hemoglobin but they can't unlock what that means for performance because they've lost elsewhere. Performance is not simply a function of how much hemoglobin you have. There's also the metabolic, can you supply the enzymes from since the mitochondria and so on.