For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
The average person's skin weighs twice as much as their brain.
131
If you are cold you are more likely to be hungry because you use energy to keep warm.
143
Every year your body replaces 98% of your atoms.
119
The human brain doesn't stop developing until about 25 years old.
102
Your heart will pump about 212 million liters in its lifetime.
26
The average sperm cell swims at 8 inches per hour.
76
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127