夏令時如何打亂你的生理時鐘

Daylight saving time, or DST, is a system where people adjust their clocks forward by one hour in the spring and back by one hour in the autumn. This practice is meant to give us more daylight during the working day, but it can have some surprising effects on our health. DST was first introduced in the UK during World War One to help save energy and make the most of daylight. Today, about 70 countries, including the US, use DST. In the US, clocks go forward in March and back in November.

When the clocks go forward in spring, people lose an hour of sleep. This might not seem like a big deal, but research shows that it can lead to more heart attacks and car accidents. The reason is that our bodies have an internal clock called the circadian rhythm, which helps us know when to sleep and wake up. When the time changes, our bodies get out of sync, making it harder to fall asleep and wake up naturally. Studies have found that the number of heart attacks rises by about 4 percent after the spring clock change. There are also more car crashes, and some people feel more anxious or depressed.

The extra light in the evening can make it harder to fall asleep because our brains produce less melatonin, the hormone that helps us feel sleepy. Darker mornings mean people wake up before their bodies are ready, leading to tiredness and stress. People who work shifts, like nurses or factory workers, are especially affected because their schedules are always changing. They have higher rates of health problems, including heart disease and diabetes.

When the clocks go back in autumn, people get an extra hour in bed, but most do not use the full hour to sleep. Some studies show that people only sleep a little longer, and some even feel more tired or sad after the change. In Denmark, researchers found that depressive episodes increased by 11 percent after the autumn clock change. However, there are some benefits, like people feeling more energetic and happier for a short time.

Overall, the negative effects of the spring clock change are stronger than the positives in autumn. Changing the clocks twice a year can cost economies a lot of money because people feel tired and less satisfied with life. Some experts think it would be better to stop changing the clocks and keep the same time all year. Most scientists believe that winter time is better for our health because it matches our natural body clocks.

So, while daylight saving time was meant to help us, it can actually make us feel tired, stressed, and even cause health problems. If you find it hard to adjust when the clocks change, try to get enough sleep and take care of yourself. Good sleep is important for your health and wellbeing.