It takes about 20 seconds for a red blood cell to circle the whole body.
102
The human brain doesn't stop developing until about 25 years old.
102
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Staying awake for 17 hours is the same for your body as drinking 2 glasses of wine.
193
One human hair can support 3 ounces.
191
The average person's skin weighs twice as much as their brain.
131
The human brain uses approximately as much energy as a 10 watt light bulb.
120