SLEEP

13 Sep 2018

130. SLEEP - THE NEW EXERCISE

Sleeping badly or for too little each night has been shown to have risks to your wellbeing and performance that are both wide ranging and potentially serious.

Words: Dr Dorian Dugmore

We can thank technology for many things, but it must be held accountable for contributing to one of the biggest wellbeing-related problems of our time, lack of sleep. 70 per cent of British people sleep for less than the recommended minimum of seven hours a night, while a third get by on only five or six.

Thanks to technology, many of us are able to work and socialise 24 hours a day if we choose to, and even when we have clocked off for the day we continue to interact with all the digital technology around us. This reliance on smartphones and apps, computers and social media means we are now less able to switch off and relax, and in particular to fall and stay asleep.

The problem is compounded by the effect of the short wavelength artificial “blue light” that is emitted by most digital devices, which is interpreted by the brain as sunlight and so confuses its natural circadian rhythm. Sleep physiologist Dr Guy Meadows calls this ‘social jet lag’ and it can compromise our health and mental functions considerably.

ASLEEP ON THE JOB

Persistent, long-term sleep problems have been linked to a higher risk of premature dementia, high blood pressure, heart disease and cancer. Lack of sleep also causes us to crave foods that are high in fats and sugar, which over time can contribute to weight gain, and affects glucose regulation, raising the risk of diabetes.

In terms of performance, the long-term consequences of poor sleep go way beyond simply feeling tired and below par. Research has shown that it affects our ability to focus, innovate, make sound decisions and lead with confidence.

Drowsiness in itself can have disastrous effects. Major international disasters, including Chernobyl, Exxon Valdez and the Challenger shuttle explosion, have been attributed to human error due to extreme tiredness, while closer to home the Croydon tram derailment and around a fifth of all accidents on major roads have been shown to be sleep related.

Sleep also plays an important role in storing and retrieving memories and could be increasingly important as we age. Over the years, our ability to process information slows down so, for example, it takes twice as long to process auditory information in our 70s compared with our 20s. There are, however, ways that we can improve this function, and the quality and quantity of deep sleep appear to be key.

Recent research suggests that we get less deep sleep as we age and as this declines so does our cognitive ability, which may then be linked to early dementia and a host of other related illnesses.

THE SLEEP CYCLE

Given the importance of our slumber on both performance and wellbeing, it’s understandable that sleep is now being hailed as the new exercise. So what should you know to get a good workout?

It helps to have an understanding of what’s going on between when we drop off and wake up again, known as the sleep cycle. There are three phases to the cycle, the first phase being ‘light sleep’, during which the breathing and heart rate slow, temperature drops and muscles relax as the body prepares itself to rest and recover. This is followed by the ‘dream’ or ‘REM sleep’ phase (Rapid Eye Movement), when the body almost feels like it’s in a state of suspension. Vivid dreams may occur and the body starts to repair itself from the day’s challenges. Then comes what many consider to be the most important phase of sleep, ‘Delta’ or deep sleep, when the body undergoes more cell repair and recovery.

The whole cycle normally lasts for around 1.5 hours and ideally should be repeated five or six times a night. Then, as morning approaches and light begins to appear, cortisol levels in the body increase and you start to wake up.

Understanding this cycle is especially useful if you’re really tired and drained and fancy a nap. A nap may help you to feel refreshed, but only if you limit it to the length of your light sleep phase, around 25mins, or sleep for a full 90 mins, one complete sleep cycle. Anything in between and you’re likely to feel groggier when you wake up than you did before. You may also find that you sleep worse that evening having had a disturbed sleep cycle.