Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
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
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
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
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
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197