It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Every year your body replaces 98% of your atoms.
119
The human brain doesn't stop developing until about 25 years old.
102
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The average person's skin weighs twice as much as their brain.
131
The human body contains over a billion miles of DNA.
147