Your thumb is about the same size as your nose.
124
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
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
Every year your body replaces 98% of your atoms.
119
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
The human brain doesn't stop developing until about 25 years old.
102
Chewing gum boosts your brain power.
285