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
The average sperm cell swims at 8 inches per hour.
76
The human brain doesn't stop developing until about 25 years old.
102
Most of us have microscopic, worm like mites named Demodex that live in our eyelashes and have claws and a mouth.
-137
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
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55