Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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
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 you are cold you are more likely to be hungry because you use energy to keep warm.
143
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Your body is creating and killing about 2.4 million red blood cells per second.
17