30 . An 18 yo male training for a 20 k marathon one hot July day just outside the Mohave Dessert has been hydrating regularly. During 3 hours of running the young man drank approximately 9 liters of water. Training was difficult and he sweated a great deal. Suddenly he lost consciousness and was taken to a hospital where blood work revealed hyponatremia (a very low sodium level): Blood pressure Iow, heart rate high: Why did this athlete lose consciousness? A) it was a hot day and he was dehydrated B) too much water in his stomach C) excessive water in his bloodstream made the blood hypertonic D) water moved by osmosis into the brain tissue causing swelling E) he was exhausted from training and needed rest
Added by Sharon C.
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However, we also know that he was sweating a lot, which means that he was losing fluids and electrolytes (like sodium) through his sweat. Show more…
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