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
Coughing can cause air to move through your windpipe faster than the speed of sound - over a thousand feet per second!
197
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
The human brain uses approximately as much energy as a 10 watt light bulb.
120
When you take a step, you are using up to 200 muscles.
885
The average sperm cell swims at 8 inches per hour.
76
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22