Getting more sleep has been linked to yet another health benefit: It may help smokers quit. Researchers at the University of Ulm in Germany surveyed 500 smokers about their sleep habits and then monitored them for 13 months, during which time 53 of them stopped smoking. The participants with longer sleep times were significantly more likely to quit; every additional hour of sleep increased their chances by 48 percent. People who are chronically overtired may depend on cigarettes to stay alert and be unable to tolerate the insomnia that often accompanies nicotine withdrawal, says lead study author Kilian Rapp. Though the link needs to be confirmed in further studies, it seems advisable to achieve a "good state" by being well-rested when trying to stop smoking, he says.