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
There's 100 trillion good bacteria living in your body.
17
If every muscle in your body could pull in one direction, you could lift nearly 25 tons.
12
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
If you are cold you are more likely to be hungry because you use energy to keep warm.
144
You can hear the blood flowing through your ears if you find a quiet place and cover them tightly.
19