Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Your heart will pump about 212 million liters in its lifetime.
26
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
The human brain doesn't stop developing until about 25 years old.
102
When you take a step, you are using up to 200 muscles.
886
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149