The human brain doesn't stop developing until about 25 years old.
102
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
One human hair can support 3 ounces.
191
The average person's skin weighs twice as much as their brain.
131
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
When you take a step, you are using up to 200 muscles.
886