The viruses that cause the common cold are always lurking. But consider this: Even if we touch a doorknob or keyboard that's covered in cold germs from an infected person, we don't always catch the cold.
"Sometimes when we're exposed to viruses, we end up not getting sick," says Aric Prather, a psychologist at UC San Francisco, who studies how our behaviors can influence our health.
Our immune systems often fend off the viruses that cause colds. But, how well our bodies mount this defense can vary.
Prather wanted to document the extent to which a good night's sleep is protective. So, he and a group of colleagues recruited 164 healthy men and women — their average age was 30 years old — to take part in a study. Using sleep diaries and a device similar to a Fitbit, the researchers assessed each participant's sleep for a week.
Then the scientists sprayed a live common cold virus into each person's nose.