Every year your body replaces 98% of your atoms.
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It takes twice as long to lose new muscle if you stop working out than it did to gain it.
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Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
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Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The largest cell in the human body is the female egg and the smallest is the male sperm.
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An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
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