"In winter I get up at night / And dress by yellow candle light / In summer, quite the other way, I have to go to bed by day..."
Children have recited this poem by Robert Louis Stevenson for generations to capture the strangeness of adjusting sleep to the shorter days that accompany the change of seasons. Heading to work in the dark and coming home after sunset can definitely throw off your sleep patterns. The lack of light that comes with wintertime is hard to adjust to for many people. Take a look at how the change of seasons can affect your sleep and what you can do to keep your sleep schedule healthy, even with shorter days.
Exposure to light is one of the key factors that governs your circadian rhythms, the biological clock that tells you when to feel sleepy. The production of melatonin, the hormone that increases feelings of sleepiness, is delayed by exposure to light and triggered by darkness. That means that as the sun goes down earlier, your body starts to prepare for sleep earlier. If the sun sets at around 4:00 p.m., you may still have work ahead of you, but your body thinks it's time for bed.
Your wakefulness in the mornings is also affected by the limited daylight of wintertime. Exposure to light in the morning stimulates cortisol production and other hormones that regulate your body and get it revved up for a new day. If you wake up when it's dark out, your body isn't receiving the clues it needs to get the day started. No wonder you feel sluggish as you head to work.
These issues are particularly noticeable in northern latitudes, where wintertime brings late sunrise and early sunset. They're also made worse by the temperature drops that come with winter. The body's core temperature drops by up to about 3 degrees Fahrenheit to help your body prepare for sleep. As the surrounding air gets cooler with winter, it encourages your body temperature to drop, which combines with the light clues your eyes are receiving to let you know it's time to sleep.
What does it feel like to cope with sleep during the shorter days of winter? Not great. Many people find they actually need an hour or two more sleep during the winter, especially if they live in northern latitudes. Researchers have even found that attention levels and the ability to concentrate drop during the short days of winter due to the "winter blues." The brain simply decides it doesn't want to work at peak efficiency when it's dark out.
Many people find their energy levels and mood are affected by the change of seasons and related lack of sleep. For some people, however, the effect is even more drastic. Up to 6% of the population experiences seasonal affective disorder, or SAD, which is a type of clinical depression triggered by the onset of winter's shorter days. People with SAD may require an extra couple of hours of sleep per night just to cope.
Fortunately, you can take steps to maintain a healthy sleep schedule during the winter months. Try these tips to enjoy good sleep during the shorter days and limited light of winter.
By paying attention to your own moods and alertness, as well as taking into consideration your sleep schedule and the types of light you're exposed to, you can manage to get healthy sleep even when the shorter days of winter try to throw you off track.
© 2020 American Sleep Association.