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
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Poor eyesight (myopia) is associated with higher IQ.
232
Enamel is hardest substance in the human body.
61
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Your body is creating and killing about 2.4 million red blood cells per second.
17
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127