Rolling over and ignoring the alarm clock in the morning may seem harmless enough.
But those lie-ins could be putting your health at risk.
Sleeping more than eight hours a night significantly increases your chance of a stroke, research suggests.
A study of nearly 290,000 people found seven to eight hours’ sleep a night may protect against the chance of a stroke.
But the US researchers, from the New York University School of Medicine, found that those who sleep for longer than this increase their risk of having a stroke by 146 percent.
And less than seven hours of sleep also increases the risk, by 22 percent.
The academics, who presented their findings at the American Stroke Association Meeting in Los Angeles yesterday, analysed factors that contribute to the risk of strokes.
They took into account the health, lifestyle, age and ethnicity of 288,888 adults who took part in a survey from 2004 to 2013.
The researchers also analysed how long people slept and how much exercise they took, such as walking, swimming, cycling or gardening.
Sleeping seven to eight hours a night and taking 30 to 60 minutes of exercise three to six times a week gave the maximum benefits for stroke prevention.
Strokes occur either as a result of a bleed on the brain or when a clot cuts off the blood supply to part of the brain. Each year in England, about 110,000 people suffer a stroke.
It the third most common cause of death, after heart disease and cancer. And brain injuries caused by strokes are a major cause of adult disability.
Smoking, being overweight, not taking much exercise and a poor diet each raise the risk of stroke.