Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
When you take a step, you are using up to 200 muscles.
886
Chewing gum boosts your brain power.
285
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
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