Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Enamel is hardest substance in the human body.
61
The average sperm cell swims at 8 inches per hour.
76
Every year your body replaces 98% of your atoms.
119
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
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
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99