The Importance of Sleep

"Scientists have discovered a revolutionary new treatment that makes you live longer. It enhances your memory, makes you more attractive. It keeps you slim and lowers food cravings. It protects you fromcancer and dementia. It wards off colds and flu. It lowers your risk of heart attacks and stroke, not to mention diabetes. You’ll even feel happier, less depressed, and less anxious. Are you interested?”

-Matthew Walker, Why We Sleep

The above, a passage from Matthew Walker’s Why We Sleep, jokingly outlines how one might peddle the astounding benefits of getting adequate sleep as if it were a new pharmaceutical.  Humorous though this is, it really is no joke.

One doesn’t have to look far on the internet or social media to find some new diet, supplement or wonder-drug which promises to exert a great many effects like those listed above.  Nine times out of ten, it is suggested that they do this by boosting levels of the body’s own hormones: Hormones which, for example, speed up metabolism, burning more fat, increase muscle growth, or more effectively utilise stores of energy.

Such claims are grossly over-inflated at best and outright false at worst.  Such products are often costly and time consuming.  Diets that promise this may be highly restrictive and require significant lifestyle change.

However, certain things are well proven to optimise the normal function of our own systems.  High among them are exercise, sleep, and maintaining healthy lean body mass.  Exercise and sleep work hand in hand to optimise health and lean body mass, but the best exercise regimen in the world is nothing without sufficient sleep.

We think of exercise as healthy.  However, this isn’t quite the case.  What is more true is that exercise places considered, careful and structured stress on the body and its systems.  It stresses the heart and lungs, the muscles, joints and connective tissues (which particular structures and systems and to which degrees depends on the type of exercise).  In response to this, the body creates beneficial adaptations.

As such, exercise could be said to create a deficit in the health and wholeness of our bodies.  Adequate rest allows the body to make up this deficit and more, making us healthier, stronger, and fitter.

It is the body’s response to the stress that exercise places on it that makes us healthier.

A great many of these beneficial adaptations occur as we sleep and all of them require sufficient sleep to work well.  A major part of this is for the body to repair itself and to hyper-compensate in the repair process, making its structures stronger, more robust, and more resilient.

If we don’t get adequate rest, particularly sleep, we miss out on these benefits.  Not only this, without adequate sleep, the body can’t keep up with the repair required to hyper-compensate for the stress placed on it by exercise.  This means not getting the most out of the effort we put in with exercise.  Even more than that, it significantly increases the likelihood of injury.

Imagine a scenario where you had a significant amount of money in a savings account.  That account would earn interest of 2% if left alone.  It also offers a bonus interest rate of 20%, if you pay an additional amount in each month.  This amount is affordable to you.  It might take some sacrifice, but it will net you an enormous additional return on the investment you are already making.

Focussing on exercise without prioritising adequate sleep is like not making the additional contributions to earn that sweet bonus interest rate.

This all pertains only to the effects of sleep on post-exercise repair and adaptation.  Sleep has numerous other benefits.  As Matthew Walker said in the quote at the beginning of the article, it exerts the following effects:

  • Improves memory.
  • Boosts the immune system.
  • Has protective effects against cancer, dementia, cardiovascular disease, and diabetes.
  • Improves mood.
  • Decreases severity of anxiety and depression.

Many of us might complain that with all we have to fit into life, we would be hard pressed to get the recommended 7-9 hours of sleep every night.  However, getting adequate sleep may be one of the highest leverage health promoting behaviours we can engage in.

With a list of positive benefits like that, it may be well worth our every effort to get more and better sleep.

Blog post written by Martin Collyer.

2nd Year Physiotherapy Student, Yoga Teacher & Trainer, Dance & Movement Teacher