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
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
The adult human brain weighs about 3 pounds (1,300-1,400 g).
99
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Chewing gum boosts your brain power.
285
After age 30, the brain begins to lose about 50,000 neurons per day - shrinking the brain .25% each year.
55