Total starvation is a very extreme situation in one sense. On the other hand, as stressed in the earlier part of this chapter, it involves a relatively gradual adaptation. The flux through any particular metabolic pathway changes over a period of days or even weeks. Exercise represents a different type of extreme situation. In sprinting, for instance, it has been estimated that net flux through the glycolytic pathway in muscle increases at least a thousand-fold, and this must happen within a few seconds or even less. In strenuous endurance exercise, such as cross-country skiing or elite marathon running, the rate of whole-body energy expenditure increases by something like 18-fold over the resting level. This involves major changes in the transport of substrates through the blood, which could not be achieved without coordinated physiological changes, in the circulatory and respiratory systems, and metabolic changes.

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Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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