It takes about 20 seconds for a red blood cell to circle the whole body.
102
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Poor eyesight (myopia) is associated with higher IQ.
232
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22