It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Enamel is hardest substance in the human body.
61
The average sperm cell swims at 8 inches per hour.
76
Every year your body replaces 98% of your atoms.
119
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
An Indian man known as "Snake Manu" can put small snakes, including deadly cobras, into his mouth and pass them out through his nose.
59