Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
Every year your body replaces 98% of your atoms.
119
If your DNA was stretched out it would reach to the moon 6,000 times.
256
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Your body is creating and killing about 2.4 million red blood cells per second.
17
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