Adrenaline Increases and Metabolism Speeds Up Most people expect that a period of fasting will leave them feeling tired and drained of energy. However, the vast majority of people experience the exact opposite: they feel energized and revitalized during fasting. Partly this is because the body is still being fueled—it’s just getting energy from burning fat rather than burning food. But it’s also because adrenaline is used to release stored glycogen and to facilitate fat-burning, even if blood sugar is high. The increased adrenaline levels invigorate us and stimulate the metabolism. In fact,
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