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Why do the clocks change - and how much sleep do you need?

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Published on 26 March 2021

Spring forward
Spring forward

It’s that time of year again. The clocks are going forward this weekend, signifying the start of spring and warmer weather.

And while many of us may bemoan losing that hour lie-in at the weekend, Dr Derek Watson, Associate Professor in Cultural Management at the University of Sunderland, believes it’s also a good time to start thinking about the importance of sleep.

Here he looks at why the clocks change and offers his tips on improving our health and wellbeing by simply getting the right amount of shut-eye each night.


Like it or not, we are about to participate in an experiment, along with 1.6 billion global citizens residing in 70 countries in which we adjust our clocks from what is called Greenwich mean Time (GMT) to British Summer Time (BST).

This event happens on the last Sunday in March and October, hence the saying, ‘spring forward, fall back’.  It was first proposed by advocates, such as Benjamin Franklin in 1784 and William Willett in 1907, who stated that this would reduce energy consumption, enhance time for leisure, exercise and tourism and became statutory under the British Summer Time Act of 1916. 

In 2019, the European parliament voted to scrap the clock changes in the EU, which are to be implemented as soon as 2022 with questions raised if the UK does not step inline. There are compelling facts to support the abolition of this century old ritual. When we lose one hour of sleep there is an average 24% increase in heart attacks in the proceeding days and 1.23 million lost working days each year. Further studies estimate that the number of fatalities caused by road traffic accidents could be reduced by 4.5% and save the economy £160m, all of which are a corollary to our sleep disruption.

The importance of sleep cannot be underestimated and is a biological necessity. There is a great deal of truth in the saying ‘the shorter your sleep the shorter your life’.

Evidence shows that your body defenses drop by 70% if you do not get enough sleep which can be linked to carcinogens, heart disease, stress, etc. despite the fact that the average person sleeps 36% of their life and we have approximately 1,460 dreams a year, (which is the same distance in miles from Sunderland to Rome). Our lifestyle choices are often the catalyst for a widespread sleep deprivation, and in consequence, it is one of the key public health challenges in 2021.

However, there is still a stigma associated with the need to sleep and this is best described by Margaret Thatcher who said ‘sleep is for wimps’ and many people still associate it with laziness and illness.

On average, we need seven to nine hours of sleep each day. When we deprive ourselves, we exhibit memory loss, fallible decision making, depleted creativity, impulsive stressful behaviour, weight gain, cardiovascular disease and ageing. In response, a growing number of sufferers respond to combating their tiredness with caffeine, alcohol and recreational drugs.

If you are suffering from sleep deprivation, tell-tale indicators are that you need an alarm clock to wake up, struggle getting up, requires increased stimulants and often being irritable to family, friends and co-workers.

Dr Michael Breus states that we have a sleep chronotype and has grouped chronotypes under four mammal behaviours. The Bear chronotypes wake up early, feel a slight waning in the afternoon and require an early night. Lion Chronotypes also rise early but struggle in the late afternoon and require an early night. Wolf chronotypes dislike early rises and prefer late nights. Dolphin Chronotypes are sensitive light sleepers and often suffer the symptoms of insomnia.

There are two types of sleep: non-rapid eye movement (NREM) and rapid eye movement (REM).

A good night’s sleep will need to embrace both types and usually follows an interchange every 90 minutes. However, the ratio changes during the first half of sleep, as the 90 minute cycles experience little REM, commonly called the deep sleep.

This process is rather like storing new information into files whilst the body repairs and grows. The latter half cycles consist of more REM sleep and feed new learning into memory, often involving deep dreams up to an hour. Evidence indicates that poor sleep patterns prevent each of these stages and give rise to poor learning and health.

 On average, over 35% of people struggle to get a minimum of seven hours sleep and the following advice may provide a better sleep culture:

  • Regularity is key: Go to bed and wake up as set times, including weekends
  • Temperature: Keep the room temperature to 65 degrees, so that the body temperature drops  two-three degrees as it is always easier to fall asleep in a cool room.
  • Bed Maintenance: Invest is a good mattress and pillows; use a mattress cover to seal off dust and mite droppings, change pillows every six months (if not sooner) and try sleeping with a pillow between your legs.
  • Caffeine: Avoid caffeine drinks after midday.
  • Alcohol: Produces both a stimulant and sedating effects. It hinders important REM sleep.
  • Water and food:  To stop sleep interruptions, avoid taking water and food at least two hours before sleep.
  • Power down: Start unwinding and stop work at least one hour before your sleep time routine commences.
  • Bedroom: Ensure your bedroom is restricted to sleep and amorous congress.
  • Lighting and noise: Ensure your bedroom has dim lights, electronics are hidden away and noise is isolated.
  •  Bathroom: Do no undermine the previous initiatives by stepping into a bright bathroom to brush your teeth and when visiting the loo.