Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
When you take a step, you are using up to 200 muscles.
886
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
Your body is creating and killing about 2.4 million red blood cells per second.
17
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
Yawns are more contagious among people with closer relationships.
163
The average person's skin weighs twice as much as their brain.
131