It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The average person's skin weighs twice as much as their brain.
131
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Enamel is hardest substance in the human body.
61
The average sperm cell swims at 8 inches per hour.
76
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55