How daylight saving affects your sleep

Setting our clocks forward in spring is a real challenge to our body clock. Photo / Getty

Today might just be the toughest Monday of the year: You're up an hour earlier, you'll be hungry for lunch at 11 and come 5pm, you'll feel like work should have ended an hour ago. Welcome to daylight saving.

For some, none of the above will really register but for others, daylight saving can hit us like mini jet-lag, leaving us feeling out of sorts for several days as we adjust to a new clock.

Here's why daylight saving can wreak havoc on our mood and sleep, and some tips for getting through the first week of earlier starts.

Spring forward

Setting our clocks forward in spring is a real challenge to our body clock. We will lose an hour rather than repeat it, plus we have to adjust our body clock earlier by an hour; the opposite to its natural tendency.

This means we're likely to have trouble getting to sleep on the first Sunday at the start of daylight saving time and the week will start with a loss of sleep and mini jet-lag. Studies have shown daytime functioning is impaired for several days and the rate of car accidents increases on the Monday following the shift onto daylight saving time.

How to adjust

• Meal times

You may find yourself feeling hungry at different times and be inclined to not want dinner until later in the evening. But it's important to give yourself time to digest your meal before heading off to bed - a heavy meal in your stomach will interfere with your ability to relax, impacting your quality of sleep.

• Ditch the evening drink

Alcohol can disrupt your sleep cycle, so don't depend on a nightcap to help you get to sleep. Other foods to avoid before bed are fried and spicey foods and refined carbohydrates.

• Hit the lights

You can help readjust your body's circadian rhythm by exposing yourself to variations in light at certain times.

In the evenings, dim the lights earlier to help your body prepare for sleep. In the mornings, try to expose yourself to light by turning on lights as soon as you get up. Spending some time outside during the course of your day will also help you reset your internal clock.

How your internal body clock works

The primary body clock, located in the brain, keeps the rhythmic variations of a number of bodily and behavioural functions - such as hormone production, temperature and digestive function - in synchrony with each other.

It also determines when we are alert and are sleepy (and prone to making mistakes if not safely in bed asleep). This process is called a circadian rhythm: "circa" (about) "dian" (a day).

This body clock is endogenous, meaning it keeps its own time. Therefore, after the transition off or onto daylight saving time, our circadian rhythm of sleepiness/alertness is an hour out of sync. It's a bit like having very mild jet lag.

The body (brain) clock is physically located about three centimetres behind the eyes and supplies information about light intensity (day versus night). Given that it receives input from the eyes, the clock can be nudged a bit earlier with light stimulation in the morning or later by light stimulation in the late evening.

Therefore, even on normal weekends without the backward clock change, sleeping in late can leave you feeling sleep-deprived the following week.

- The Conversation and NZ Herald

Content in this article was originally published on The Conversation. Read the original article.