Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
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
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Chewing gum boosts your brain power.
285
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
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