It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
It takes about 20 seconds for a red blood cell to circle the whole body.
102
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
Enamel is hardest substance in the human body.
61
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Poor eyesight (myopia) is associated with higher IQ.
232
One human hair can support 3 ounces.
191
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118