It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
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
The human body contains over a billion miles of DNA.
147
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.
682
Poor eyesight (myopia) is associated with higher IQ.
232