The focusing muscles of the eyes move around 100,000 times a day. To give your leg muscles the same workout, you would need to walk 80km (50 miles) every day.
21
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
22
The human brain uses approximately as much energy as a 10 watt light bulb.
120
If you hold farts in during the day, they'll just come out when you sleep.
16
There are about 1,400 different species of bacteria in your belly button.
10
For most people, no matter how hard you pinch the skin on your elbow with your fingers it doesn't hurt.
515
In one day, adult lungs move about 10,000 litres of air.
11