It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Enamel is hardest substance in the human body.
61
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
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
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain doesn't stop developing until about 25 years old.
102
Our Right Lungs takes more air than our left lung.
194