The average sperm cell swims at 8 inches per hour.
76
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
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
Stress can result in more headaches as a result of the body rerouting blood flow to other parts of the body.
92
Quick naps not only improve your alertness, but they also help in decision making, creativity and sensory perception.
149
Oxygen, carbon, hydrogen and nitrogen make up 90% of the human body.
118
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