Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
When you take a step, you are using up to 200 muscles.
886
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
One human hair can support 3 ounces.
191
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.
73
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
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