Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
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
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193