You should feel rested after clocking roughly eight hours of sleep [1]. More accurately, "the National Sleep Foundation recommends seven to nine hours a night, and that's usually what I give my patients as a guide," Daniel A. Barone [2], MD, a neurologist at New York-Presbyterian and Weill Cornell Medicine and author of Let's Talk About Sleep [3], told POPSUGAR. But every person is different, and there are periods in your life when you may need more sleep than average.
One of those is during pregnancy. Your body goes through a lot of changes when you're pregnant, from hormonal shifts to weight gain, which may cause you to have less energy. Plus, "it's possible for pregnant women to develop sleep apnoea," Dr. Barone said, a condition in which the airways close off during the night [4]. "This causes the brain to wake up and prevents you from getting into the deepest sleep, called delta wave sleep. Sleep is not just about quantity, but quality," he explained. Fortunately, treatment can help. If you notice that you're snoring or find that you wake up more frequently during the night [5], at times feeling like you're gasping for air, talk to your ob-gyn.
Similar to pregnancy, the harder you push your body — by training for a marathon, for example — the more rest and recovery you need. "If you're doing intense athletic competition or training, sleep is the time when your body repairs itself," Dr. Barone said. "And especially during the deepest stage of sleep — that is when growth hormones are produced."
Otherwise, needing more than eight or nine hours of sleep [7] to feel rested may be a sign of an underlying condition, like sleep apnoea, narcolepsy, or clinical depression, among others. It's important that you get to the bottom of it, as proper treatment can often help ease the symptoms and restore your energy. "If you're always more tired than your friends, talk to your primary care doctor about it," Dr. Barone said.