Yawns are more contagious among people with closer relationships.
163
It takes about 20 seconds for a red blood cell to circle the whole body.
102
The average sperm cell swims at 8 inches per hour.
76
When you take a step, you are using up to 200 muscles.
886
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
Dogs can be trained to identify the scent of lung cancer long before symptoms develop.
190