Sleep - How much do you need for health and long life?
Both too much and too little sleep can reduce your life expectancy (1). The optimal sleep for a long life seems to be between six and seven hours per night, according to a study of 1.1 million men and women. During the study period, the risk of death increased by 15% for those who slept eight hours, and 20% for those who slept nine hours per night. Sleeping less than four hours also significantly increases death rates.
Don't worry too much about the number of hours sleep that you get however, unless you are at an extreme. The regularity and depth of your sleep is much more important. Several studies show that a regular daily schedule is more important for your health and longevity. This means going to bed and rising at the same time every day, weekends included. Regular daily habits not only apply to sleeping, but also to eating, exercise and a large part of your lifestyle. Maintaining consistent Circadian rhythms will insure health much more than a nine-hour night followed by a five-hour night. Regularity will help you to sleep deeply and avoid insomnia.
Not everyone needs the same amount of sleep. You can check your body type here, to get a good idea of the sleeping habits, diet and particular foods, climate, lifestyle, social habits and other factors that will best help your state of health, both mental and physical.
1. Kripke, Daniel.
Archives of General Psychiatry, 2002, February.