Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
The human brain uses approximately as much energy as a 10 watt light bulb.
120
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
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