Adjusting your body clock when the time changes

Adjusting your body clock when the time changes
Dr. Karyn Esser is a professor of physiology at the University of Kentucky. She specializes in targeting circadian rhythms to optimize health and directs the Center for Muscle Biology. 

As we reset our clocks and watches for daylight saving time, it's a good opportunity to think about our body clocks as well. Our bodies naturally operate on 24-hour cycles, called circadian rhythms, that respond to external cues such as time of light and dark, eating and physical activity.

While we often think of the body as having one "" in the brain, current science now makes it clear that every cell in the body has its own individual clock. Together, these timekeepers direct our behaviors—telling us when to sleep, wake up and eat— and work to keep our cells healthy.

When we set our clocks back an hour each autumn, we don't see it as anything more than gaining an extra hour of sleep. In reality, though, all the cell clocks in our body are making an adjustment to this change in time. Even this small time change can cause our body clocks to become slightly and temporarily out of sync. As a result of the time change, for about a week you might feel tired earlier at night and wake up earlier in the morning. The good news is that the fall , where we delay the clocks and our exposure to light by an hour (known as a "phase delay"), is easier for us to adjust to than setting our clocks forward.

For best health we need to be mindful our body clocks all year long. Minor changes like can have small, temporary effects on us. But long-term disruptions to your circadian rhythm, like , shift work, or eating and exercising late in the day, can cause more serious problems. According to the National Institutes of Health, abnormal have been associated with obesity, diabetes, cardiovascular disease, depression, bipolar disorder and .

How do you keep your body clock in healthy working order year round?

  • Use light as your guide. The best way for you to keep your body clocks synchronized is to keep light, eating, and activity consolidated. Use daytime hours for your meals and exercise, and try to do most of that earlier in the day.
  • Get enough sleep. Sleep serves an important function - it's when our bodies do maintenance, which is why our body clock tells us to go to sleep every day. Try to get about eight hour of sleep each night.
  • Pay attention to your natural time cues of light exposure, when you eat, and when you're physically active/exercising. Your sleep cycle is an output of your system, and eating, exercising, and bright lights (including your cell phone, computer or TV) near bedtime can make it difficult to sleep.
Citation: Adjusting your body clock when the time changes (2014, November 4) retrieved 27 September 2023 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Explore further

Sleep disrupted? maybe it's Daylight Saving Time


Feedback to editors