We are now well into the winter months and you may have noticed a disruption to your sleep over the past few months, with difficulties getting to sleep, maintaining sleep or struggling to get up in the morning. This can impact on how you feel the next day, resulting in daytime tiredness and lethargy, lack of motivation and low mood. Below I explore the factors that may contribute to this winter sleep disruption.
One of the biggest influences on our sleep is light exposure and obviously this is reduced in the winter months. Light exposure during the day is needed for the production of melatonin later in the evening, the hormone that regulates the timing and duration of sleep. It is the contrast between light exposure during the day and during the evening that is recognised by the brain as a signal for sleep. In the winter, not only is there less sunlight but we also tend to spend much more time indoors so we miss out on natural daylight exposure. With less daytime light exposure, melatonin concentrations are generally lower and this can cause sleep disruption. In addition, the low level of light exposure may lead to feelings of tiredness during the day. This is because melatonin concentrations normally start to rise when light levels begin to dim in the evenings, a few hours before we go to sleep. So in the winter, with low levels of light exposure throughout the day, the timing of melatonin onset may be earlier, as the sleep systems in the brain become confused, leading to feelings of tiredness and lethargy.
Try to spend more time outside in the winter months in order to get an adequate level of light exposure. Going for a walk in your lunch break is a good way to achieve this or walking/cycling to work or part of the way to work. Make sure your work and home environments are as light as possible during the day. Open your curtains and blinds as soon as you wake up in the morning and try to sit by a window at your place of work. In addition, dim your lights at home in the evening to encourage melatonin onset before you head off to bed.
Physical and mental health
Most people are aware that we are more susceptible to colds and flu in the winter. This is not because cold temperatures cause these infections but because these viruses are able to survive better in colder environments. Another factor is that people spend longer indoors so are more likely to breathe in the same air as someone who already has an infection. In addition, the reduced exposure to sunlight leads to low levels of vitamin D and this can impair our immune system. The increased use of artificial heating in the winter produces hot, dry air and this dries out your mucus membranes, making your body more susceptible to infections such as colds or flu.
Common symptoms of colds and flu are a blocked nose, sore throat, breathing problems, headaches, aching limbs and fever. Although infections can cause tiredness and an increased need for sleep, all these symptoms can disrupt your sleep making it harder to nod off or stay asleep. Adequate sleep is vital for effective immune function so these sleep disturbances can make you more vulnerable to colds and flu.
Reduced levels of sunlight and vitamin D have been linked to low mood, irritability, fatigue and Seasonal Affective Disorder (SAD). This is a mood disorder characterised by depressive episodes that occur in the autumn and winter. Besides a persistent low mood, other symptoms of SAD include a lack of energy and feeling sleepy during the day, sleeping for longer and finding it hard to get up in the morning. These symptoms can in turn disrupt an individual’s natural sleep rhythms so it is more difficult to sleep at night time. Many people notice a lack of energy in the winter and occasional low mood but for SAD sufferers these symptoms are more persistent and debilitating. SAD can be treated with light therapy so speak to your doctor if this is something that you think seriously affects you.
Spend as much time outdoors to boost Vitamin D, serotonin and melatonin production. Prioritise your sleep to strengthen your immune system so it is fully prepared to fight infections. Make sure your diet includes plenty of Vitamin C and antioxidants, nutrients needed for immune functioning, by eating fruit and vegetables and drink plenty of water.
With the shorter days and the colder temperatures, it’s hard to find the motivation to exercise in the winter, particularly if you are feeling tired. But regular, moderate exercise has been associated with better quality sleep and an increase in the portion of deep sleep you get in a night. It also is a great stress buster as it reduces some of the stress hormones that are released by the flight or fight response.
Remind yourself that any exercise is worth doing for the sake of your physical and mental health but if you can combine this with a burst of natural daylight this is a double benefit to your sleep and energy levels. However, don’t exercise too close to bedtime because this can actually disrupt your sleep as your body takes several hours to cool down to a level optimal for sleep.
With temperatures dropping in the winter, we tend to compensate by turning up the heating. While it is important that your bedroom is not too cold, environments that are too hot can be more disruptive to your sleep. In addition, artificial heating produces hot, dry air and this can lead to dehydration and dry out your mucus membranes, reducing your ability to fight infections which may disturb your sleep. If you have your heating on at night you may wake with a dry mouth or feeling thirsty and then not be able to return to sleep.
Aim for a cool bedroom in the range of 16-18 degrees Celsius as this is the optimum temperature level for sleep. Turn your heating off at night and use duvets, blankets and bed linen made from natural fibres such as cotton and wool as these will regulate your body temperature more efficiently than manmade fibres. Try the Naturalmat range of duvets and pillows made from organic wool or goose down as well as sheets, pillow cases and duvet covers made from organic cotton.