It takes about 20 seconds for a red blood cell to circle the whole body.
102
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Enamel is hardest substance in the human body.
61
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Every year your body replaces 98% of your atoms.
119
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain has the capacity to store everything that you experience.
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