Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
Your heart will pump about 212 million liters in its lifetime.
26
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
There are times when you're walking that the pressure on your feet exceeds your body weight, and when you're running, it can be three or four times your weight.
62
The human brain is very soft, having a consistency similar to soft gelatin or firm tofu.
13
When you get goosebumps and your hair stands, the hair helps to trap air, making you feel warmer by keeping in your body heat.
46
The human brain uses approximately as much energy as a 10 watt light bulb.
120
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127