Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
If your DNA was stretched out it would reach to the moon 6,000 times.
256
When you take a step, you are using up to 200 muscles.
886
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
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