Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
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 human brain doesn't stop developing until about 25 years old.
102
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
When you take a step, you are using up to 200 muscles.
886