Sleep is a much-neglected component of our physical and mental health in this frantic day and age. If we want to live happy, healthy lives, we need to give it the priority it deserves.
This week saw the publication of a study by researchers at Glasgow University, in which it was claimed that exercise improves sleep. Coming to this conclusion took a little imagination, as the study involved taking some ageing mice, disrupting their sleep cycle, and then seeing how they adapted. Half of them were given access to a running wheel. The mice that had the chance to run around caught up on their sleep and adapted much faster than those who didn't. With an impressive amount of extrapolation, it is claimed that this might apply to humans: Most of us, through the marvels of our modern lives, suffer from disrupted sleep patterns. Modern technology is staggeringly good at creating environments that are bad for sleep. As we age, we get more sensitive to the effects of these sleep-toxic environments. The mouse experiment suggests that regular exercise might help to protect our sleep patterns, particularly as we age.
Whatever you think about the value of extrapolating from mice to humans, at the heart of this study lies the fundamental importance of sleep to our health and well-being. So why is sleep so important? What constitutes good enough sleep? And how can we improve our sleep patterns?
Why is sleep so important?
Sleep is so much more than the few hours you squeeze in between finishing one day and starting the next. You can survive three times as long without food as you can without sleep. Sleep has an evolutionary advantage in terms of conserving our energies and protecting us from night-time predators, but it's about much more than hiding in our cave from the lions and tigers and bears (oh no!) outside.
There are complicated, competing theories about the functions of sleep. Let us not get too caught up in the nitty-gritty of that particular debate but focus on what is generally agreed: Sleep restores our bodies and minds on every level.
Sleep is a time when physical restoration and even growth occur. Wound healing, immune system recovery and musculo-skeletal growth all depend on adequate amounts of sleep. Sleep is crucial for brain development, particularly during infancy and childhood. Beyond childhood, it is essential for brain plasticity, that is the brain's ability to change and grow.
All sorts of different memories are processed during sleep. Any new material that has been learned is consolidated. Emotional memories – good and bad – are processed. New skills are assimilated. In order for any kind of learning to occur, there has to be sufficient sleep.
Dreaming happens during sleep. There are wildly different opinions about the function and importance of dreams, but it is generally acknowledged that being deprived of the dream phase of sleep is associated with particular mental and emotional problems.
Conversely, if you're not getting enough good quality sleep, you're at risk of exacerbating existing health conditions, increasing your chances of developing illnesses in the future, and suffering from mental health problems. You're more likely to have accidents and suffer from memory problems. Diabetes, obesity, chronic pain , heart conditions, and depression and anxiety have all been linked to sleep disturbances. Clearly, it's worth getting your sleep right.
How much sleep is enough?
There seems to be a general societal agreement that we need 8 hours of sleep per night, and this is gradually being pushed back to 7. It's not entirely clear where this consensus has come from, as sleep experts will tell you that the question of how much sleep is enough is very complicated, and very individual.
For starters, there's basal sleep versus sleep debt. Basal sleep is how much sleep you need on average to function reasonably well physically and emotionally. If you get less sleep than this over a period of time, sleep debt occurs. You can catch up on sleep debt but it takes a while. Then there's the question of quality versus quantity. It's not just the hours you sleep, but how well. And finally, just to complicate things, too much sleep doesn't seem to be brilliant for us either, and has much the same effects on our physical and mental well-being as too little sleep!
So how do we know if we're getting enough (good) sleep? A good starting point may be some basic questions:
Symptoms of sleep deprivation include sleepiness, tiredness (the two are not the same thing), poor concentration and memory, irritability and low mood. If any of these plague you on a regular basis, it may be worth looking at your sleep.
Top tips for improving sleep
First and most importantly, in order to improve your sleep you need to make a commitment to doing so and to prioritise it in your never-ending to-do list. Other things that can help include:
Making the most of environmental cues:
Finally, back to the first paragraph of this article: Exercise! Even if you're not an ageing, sleep-cycle-disrupted mouse, moderate exercise will help you to sleep better. Just don't do it too close to bedtime.