Getting enough sleep is important for many reasons. The quality of sleep as well as the amount of sleep affects our immune system. An interesting study just published, investigated whether sleep duration and efficiency in the weeks preceding viral exposure are associated with susceptibility to getting a cold (Cohen S. et al, 2009). Sleep scores were calculated for 14 days before the participants were exposed to the rhinovirus. They were then monitored for signs and symptoms indicating that they had developed a cold.
The results showed that participants with less than 7 hours of sleep were 2.94 times more likely to develop a cold than those with 8 hours or more of sleep. When sleep efficiency was graded, participants with less than 92% efficiency were 5.5 times more likely to develop a cold than those with 98% or more efficiency.
If you want to have better resistance to illness, be sure you get enough quality sleep.
Cohen S, et al. Sleep habits and susceptibility to the common cold. Arch Intern Med. 2009 Jan 12;169(1):62-7.