Time change: how does it affect health and sleep habits?

Changing the time isn’t just about moving the hand on the alarm clock forward or backward by an hour. Our biological clocks also react to this change. The time shift affects the quality of sleep and the production of necessary hormones. What effect does the time change have on health and why does it give your body a harder time than you think?

Daylight saving time: when did it all start?

Daylight Saving Time is a time change that takes place in more than 70 countries around the world. It was originally introduced to save energy and make better use of evening light. American scientist Benjamin Franklin talked about the possibility of introducing the time change as early as 1784. He thought that people would save money and candle consumption. However, this reasoning was rather ironic. The main idea was to use daylight more efficiently.

Time reversal was first introduced in 1916, pioneered by London builder William Willet. Germany, Austria-Hungary and Sweden were the first to adopt the change. A year later, Russia introduced daylight saving time and the following year America joined in. As “time changes” did not become very popular in the early years, many countries gradually abandoned them.

The return to daylight saving time occurred during World War II. The reason was simple – austerity. Specifically, saving energy for lighting. Czechoslovakia moved to annual changes between daylight saving time and standard time in 1979. And the time has been changing ever since.

Since when is the time change in the Czech Republic? It is changed to daylight saving time on the last Sunday in March. The hands of the clocks move back from 3:00 to 2:00. On the last Sunday in October, it switches back to standard time. The hands will move from 2:00 to 3:00.

How does the time change relate to our biological clock?

All living organisms have different mechanisms to adapt to their environment and its changes. Biological rhythms are divided according to their length into:

• circadian – lasting about 24 hours,
• ultradian – they consist of shorter time units (hours, minutes, seconds),
• infradian – periods longer than 24 hours (days, weeks, months, etc.).

The circadian rhythm is related to a person’s internal biological clock and lasts approximately 24 hours. It affects:

• sleep and wakefulness,
• food and drink intake,
• body temperature,
• metabolism,
• cardiovascular system, etc.

The proper functioning of the biological clock and circadian rhythm is largely related to exposure to light. It synchronises the cycles of darkness and light that correspond to day and night. Simply put, the circadian rhythm influences daytime activity and sleep at night.

What happens to the circadian rhythm when time changes?

Because of the transition between summer and winter time, the time when people are exposed to natural light changes twice a year. This disrupts your sleep-wake cycle. Therefore, you may feel tired in the morning and not yet sleepy enough to go to bed at night. Your internal clock is out of sync with the natural clock during the day. Because of the disruption of circadian rhythms, the quality of sleep also deteriorates.

Changes in daylight affect the production of hormones responsible for alertness and fatigue:

• Melatonin – the sleep hormone. It is released in the evening as daylight fades. The body becomes tired and prepares for sleep.
• Cortisol – the hormone of alertness. It increases in the morning hours. It makes you wake up and feel the necessary energy.

When daylight saving time becomes daylight saving time, there are also changes in hormone production. As it is darker in the morning, the body doesn’t produce cortisol at the necessary levels, and you may feel tired and sluggish when you wake up. In the evening, when it’s lighter, the body doesn’t trigger melatonin production at the appropriate time, so you may have trouble falling asleep.

Which time is better for health: summer or winter?

If you would like to keep the circadian rhythm and the internal clock in harmony, it would be best to “observe” the natural winter time. You are more likely to be in sync with the rotation of the Earth and the seasonal changes.

Changing to daylight saving time means losing an hour of sleep. Although this happens on a weekend (Saturday to Sunday) and you have a day to adjust to the change, a day is not enough. Especially for people who have sleep problems (such as insomnia), the reduction in sleep time can be a big problem. Equally, the change is problematic for those who work shifts.

Time change and its effect on human health

Time alternation is a burden on the human body. It doesn’t matter if it’s a change to daylight saving time or standard time. With both semi-annual changes, the risk increases:

• moodiness,
• traffic accidents,
• of a heart attack,
• sleep disorders.

Although most people get used to the time change within a week or so, some never get used to it completely.

Sleep problems plague a wide range of people. These include, for example, seniors, people with chronic diseases, but also adolescents. Long-term poor quality sleep can cause:

• reduced immunity,
• overweight and obesity,
• type 2 diabetes,
• blood pressure problems,
• Anxiety,
• depression,
• reduced ability to concentrate,
• learning difficulties,
• lower performance and productivity.

What can you do to make sure you don’t suffer so much when you change to summer or winter time?

In the days and weeks leading up to the time changes, there are a few tips you can try that can help reduce the negative impact on your sleep.

• Adjust your bedtime – go to bed 15 to 20 minutes earlier a few days before daylight saving time. If it’s winter time, go to bed 15 to 20 minutes later for a few days.
• Adjust other daily routines – for example, set meal times to fit your new regime.
• Help yourself by adjusting the light – with smart lighting, you can set gradual dawn and dusk modes to match the natural course of the day.
• Go to bed at the same time – once you’ve settled into your new time schedule, always go to bed at the same time.
• Take a nap – you can nap during the day, but in moderation. Your afternoon nap should last no more than 20 minutes.
• Make changes gradually – if you have a daily routine, such as morning walks, move them up an hour. Instead of 8am, start at 9am. Shorten the start time by 10 to 15 minutes each time. In a week, your body will get used to the time change.

Other rules of sleep hygiene

To promote quality sleep:

• sleep in a ventilated bedroom with a room temperature between 18 and 20 °C,
• Remove all distracting objects from the room (electronics, LEDs, allergens, etc.),
• try to sleep in maximum darkness and silence,
• do not drink alcohol before going to bed,
• don’t have heavy meals just before you go to bed,
• be at rest for at least 3 hours before going to bed (do not engage in any strenuous exercise),
• Do what calms you down before bed (relaxation, bath, reading a book, aromatherapy, etc.).

Support healthy sleep with a quality mattress

In order to wake up refreshed and with enough energy for the whole day, you need to sleep on a suitable mattress. It is the mattress that largely influences the quality of your sleep. An unsuitable mattress can make your joints, cervical spine, hips, shoulders, etc. ache. In addition, it is difficult to find the right sleeping position, so you wake up at night by constantly “fidgeting” to find the best position.

How do you choose the perfect mattress?

• Length – its length should be about 20 to 25 cm longer than your height.
• Mattress thickness – generally, the higher the mattress, the more comfortable the sleep. The most comfortable mattresses are those that are 20 to 30 cm or more in height.
• The firmness of the mattress – it depends on your weight and preferred sleeping position. The higher the weight, the firmer the mattress.
• Mattress material – choose the material according to your requirements for quality sleep. If your joints hurt, reach for memory foam. For allergy sufferers, natural materials such as latex, horsehair or coconut board are best. Persons who sweat a lot need a breathable mattress. Foams with an open structure are ideal. For back pain, an orthopaedic mattress with zones is suitable.
• Mattress weight capacity – it should be about 20% more than your weight.

Choosing a mattress according to your sleeping position:

• Sleeping on your back – one of the healthiest positions because the spine is in one plane and the body weight is evenly distributed. A soft to very soft mattress is best for sleeping.
• Sleeping on your side – promotes a healthy curvature of the spine and counteracts back pain. Reach for a medium to soft mattress with zones.
• Sleeping on your stomach is the least healthy position. But if you can’t sleep otherwise, make your bed on a hard mattress that won’t put strain on your spine.

For hygiene reasons, the mattress must be changed every 7 years, but sometimes it wears out sooner. How do you know if your mattress has had it?

• The mattress has visible damage (torn cover, bumps, is worn).
• The mattress squeaks.
• You wake up with pain, often turning over at night to find the best sleeping position.

Top 5 questions about the time change and its effect on sleep

The time change has been happening here for some time now, and yet there is a lot of confusion about it. We’ll help you clarify some of them.

1. Why does the time change affect sleep?

When the time changes to winter or summer, the natural circadian rhythm, i.e. the biological clock of a person, is disturbed. These regulate sleep, wakefulness, hormone production, etc. A person’s internal clock is mainly influenced by daylight, which changes due to the time change and, especially in summer, does not correspond to the natural process.

2. What hormones are affected by the time change?

It is mainly melatonin, which is released with darkness. It’s also the hormone cortisol, which the body starts producing when you wake up. It accompanies wakefulness. Because of the shift in light, these hormones are released at different times, causing problems falling asleep and sleepiness during the day.

3. How long does it take the body to get used to the time change?

For most people, the body gets used to the time shift in a week. However, there is a group of people who take longer to react to the change or never accept it. These are usually people who have trouble sleeping.

4. Which time is more natural for the body?

The body thrives best in the winter time, as it better matches the daylight changes and the biological processes of a person.