The average sperm cell swims at 8 inches per hour.
76
Enamel is hardest substance in the human body.
61
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
The human brain doesn't stop developing until about 25 years old.
102
Chewing gum boosts your brain power.
285
Your body is creating and killing about 2.4 million red blood cells per second.
17
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22