The average sperm cell swims at 8 inches per hour.
76
Yawns are more contagious among people with closer relationships.
163
An average heart beats 100,000 times a day, pumping some 2,000 gallons of blood through its chambers. Over a 70-year life span, that adds up to more than 2.5 billion heartbeats.
73
It takes twice as long to lose new muscle if you stop working out than it did to gain it.
127
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
It takes about 20 seconds for a red blood cell to circle the whole body.
102
Women have about four times as many foot problems as men; lifelong patterns of wearing high heels often are the culprit.
111