It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Yawns are more contagious among people with closer relationships.
163
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
When you take a step, you are using up to 200 muscles.
886
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
Your body is creating and killing about 2.4 million red blood cells per second.
17