How does the time change affect our biorhythm?

This weekend it's that time again: our clocks will be set back to winter time. The topic of the time change has received a lot of media attention in recent months. How does turning the clock back and forth every six months affect our biorhythm? Will summer time even exist in the future? You can find the answers in our blog post.

The switch to summer time was first introduced in Germany during the First World War in order to conserve resources. During the Second World War, the clock was also set forward by one hour. After and between the two wars, however, people went back to standard time (winter time) and the time change was discontinued. In 1980, many European countries reintroduced daylight saving time. Since then, we have set our clocks one hour forward every spring and back again in the fall.

The original purpose of the time change was to save energy, as daylight could be used for longer in summer. However, experts have repeatedly shown that this concept doesn't really work. The electricity savings are offset by the higher heating costs in spring. The time change therefore has little economic benefit, but it is said to be detrimental to health.

The end of summer time

In the summer of 2018, the time change was therefore also a topic of discussion in Brussels. The European Commission launched a public consultation on the EU summer time regulation. EU citizens were asked online about their views on the time changeover. 4.6 million participants took part in the survey. This record number shows how important the issue is to the population. The result is clear: 80% were against putting the clocks forward and back. It is now up to the member states to decide what such an end to the time change should look like in practice.

The effect of the time change on the sleep-wake rhythm

The human body is subject to a circadian rhythm. This means that our brain activity, circulation and metabolism are subject to a 24-hour cycle. Our sleep-wake rhythm is based on the alternation of day (light) and night (dark). Darkness, for example, increases the release of certain hormones such as noradrenaline and the sleep hormone melatonin. The latter regulates our sleep-wake rhythm and ensures that we become sleepy and tired towards the evening.

In contrast, when it is light, our body releases the wake-up hormone cortisol and we become fit and alert. If it is dark in the morning, we therefore find it difficult to get going. In particular, the time change from daylight saving time in spring upsets this regulatory mechanism and causes many people problems year after year. According to a survey by Kaufmännische Krankenkasse, it causes problems for every third person. Women (39%) are affected more often than men (23%). The body lags an hour behind and is still geared towards winter time. Typical problems include tiredness in the morning as well as sleep and digestive disorders.

We are curious to see how many more time changes there will be in the future and are now looking forward to sleeping an hour longer on Sunday.

Sources:

• Mutschler et al. Human anatomy, physiology and pathophysiology. 5th edition. Wissenschaftliche Verlagsgesellschaft mbH Stuttgart. 1999
• KHK press release "Every third person has problems due to time changeover" 21.03.2017.
• https://www.tagesschau.de/inland/zeitumstellung-umfrage-101.html