RELATED: 80 Percent of Strokes Could Be Prevented by Doing These 4 Things, CDC Says. A 2019 study published in the Neurology journal looked at the effects of sleep on stroke risk. The researchers for the study analyzed more than 31,000 retired employees for six years, having them complete questionnaires about their sleeping and napping patterns. Over the course of the study, more than 1,500 of the participants ended up having a stroke.ae0fcc31ae342fd3a1346ebb1f342fcb According to the study, two factors helped raise people’s stroke risk: long napping and long sleeping. People who both slept more than nine hours and reported more than 90 minutes worth of midday napping were 85 percent more likely to have a stroke than people who both moderately napped and slept. RELATED: Drinking One Glass of This Per Day Can Slash Your Stroke Risk, Study Says. You don’t have to be both a long napper and a long sleeper for your risk to be higher, however. Each of these habits raises your risk separately as well. People who took a midday nap longer than 90 minutes were 25 percent more likely to have a stroke than people who moderately napped for 30 minutes, at most. And in terms of sleeping long at night, people who slept nine or more hours a night were 23 percent more likely to have a stroke than those who slept at most eight hours per night. The study did not conclude why exactly this connection between sleeping patterns and stroke exists. But study co-author Xiaomin Zhang, MD, a professor at the Huazhong University of Science and Technology, said in a statement that long napping and sleeping suggests an “overall inactive lifestyle,” which could contribute to the increased stroke risk. “More research is needed to understand how taking long naps and sleeping longer hours at night may be tied to an increased risk of stroke, but previous studies have shown that long nappers and sleepers have unfavorable changes in their cholesterol levels and increased waist circumferences, both of which are risk factors for stroke,” Zhang said. RELATED: For more health advice delivered straight to your inbox, sign up for our daily newsletter. But it’s not just how long you sleep. According to the study, poor sleep quality also plays a part in increased stroke risk. The researchers found that the participants who reported poor sleep quality showed a 29 percent higher risk of total stroke compared with those who reported good sleep quality. When looking at both those who were long sleepers and reported poor sleep quality, the risk of having a stroke was 82 percent higher than moderate sleepers with good sleep quality. “These results highlight the importance of moderate napping and sleeping duration and maintaining good sleep quality, especially in middle-age and older adults,” Zhang said. RELATED: Drinking This Once a Day Can Triple Your Stroke Risk, Study Finds.