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
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
When you take a step, you are using up to 200 muscles.
886
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
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
Every year your body replaces 98% of your atoms.
119