London, Aug 15 (IANS) Young adults with the habit of binge-watching television shows for over three hours in one sitting may be at risk of having poor sleep quality, increased fatigue and insomnia, researchers warned. Binge viewing is when people watch an excessive amount of the same TV programme in one sitting. The findings suggest that increased cognitive arousal prior to sleep (being mentally alert) is the mechanism explaining the effects of binge viewing on sleep quality. Sleep insufficiency has been connected to physical and mental health, including reduced memory function and learning ability, obesity, hypertension and cardiovascular disease. "We found that the more often young people binge-watch, the higher their cognitive pre-sleep arousal," said lead author Liese Exelmans, a doctoral student at the University of Leuven, Belgium. "That in turn negatively affected sleep quality, fatigue and insomnia," Exelmans added. For the study, published in the Journal of Clinical Sleep Medicine, the team involved 423 young adults who were 18 to 25 years old, with an average age of 22 years. Respondents indicated they slept, on average, seven hours and 37 minutes, while 98 per cent of binge-watchers showed higher risk of having poor sleep quality. Bingeable TV shows have plots that keep the viewer tied to the screen and makes the viewer they become intensely involved with the content, A racing heart, or one that beats irregularly, and being mentally alert can create arousal (or pre-sleep arousal) when a person tries to fall asleep. This can lead to poor sleep quality after binge-viewing, the researchers said.