Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Your body is creating and killing about 2.4 million red blood cells per second.
17
Your heart will pump about 212 million liters in its lifetime.
26
When you take a step, you are using up to 200 muscles.
886
One human hair can support 3 ounces.
191
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The human body contains over a billion miles of DNA.
147