It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The human brain has the capacity to store everything that you experience.
4k
One human hair can support 3 ounces.
191
Enamel is hardest substance in the human body.
61
Your body is creating and killing about 2.4 million red blood cells per second.
17
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
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Our eyes are always the same size from birth, but our nose and ears never stop growing.
266