Yawns are more contagious among people with closer relationships.
163
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
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The average sperm cell swims at 8 inches per hour.
76
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
If your DNA was stretched out it would reach to the moon 6,000 times.
256
The average person's skin weighs twice as much as their brain.
131