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
When you take a step, you are using up to 200 muscles.
886
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
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
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
Every year your body replaces 98% of your atoms.
119