Blood PH above 7.8 in humans = Death. Normal is 7.4
Alkalosis occurs when [bicarbonate] increases forcing the equilibrium to remove protons from blood causing blood pH to rise. So pH becomes alkaline leading to vomiting, nausea, headache.
Temporary metabolic alkalosis occurs when there is an intake of sodium bicarbonate e.g. if large amounts are taken for acid in the stomach. Respiratory alkalosis can be induced by hyperventilation i.e. excessive exhalation of carbon dioxide from lungs too quickly causing too great a loss of H from the large reservoir. Anything that causes sustained rapid breathing can induce temporary alkalosis, e.g. hysteria (pop concert), hot baths, training.
Athletes such as marathon runners learn to control breathing so as to minimise alkalosis. Sprinters and swimmers who understand biochemistry tune their bodies for maximum effort. Strenuous bursts of muscle activity produce high levels of lactic acid as glucose is broken down for energy. Lactic acid can lower the pH of blood and cause muscle cramp/fatigue.
To counteract this, athletes will prepare by rapid deep breathing for 30-40 seconds before the race to hyperventilate and introduce temporary alkaline conditions that will help to neutralise the acidity arising from lactic acid.
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