It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Cracking your knuckles does not actually hurt your bones or cause arthritis. The sound you hear is just gas bubbles bursting.
18
It takes about 20 seconds for a red blood cell to circle the whole body.
102
It would take about 1,200,000 mosquitoes to fully drain the average human body of blood.
217
One human hair can support 3 ounces.
191
The largest cell in the human body is the female egg and the smallest is the male sperm.
682
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111
The human brain doesn't stop developing until about 25 years old.
102