We all know that we need sleep. Research consistently shows the negative effects of not getting enough sleep: It increases our risk of a variety of ailments, including coronary heart disease and diabetes; leads us to make errors in our daily life; can make simple tasks—such as driving—much more dangerous; and impacts our moods. The same is true for sport, and there likely isn’t an athlete around who hasn’t been told about the importance of sleep. And yet, we know that athletes, and indeed coaches, don’t get anywhere near enough, with research often reporting an average sleep duration of fewer than seven hours per night.
The Caffeine-Adenosine Link
There are various reasons for this. We ingest more caffeine than ever before, evidenced by the fact that 2.2 billion cups of coffee are consumed daily across the world. Caffeine is a stimulant, and works by blocking adenosine from binding to its receptors. Adenosine is the chemical responsible for making us feel sleepy; it builds up over the course of the day, creating something called “sleep pressure,” which makes us tired and (hopefully) sends us to sleep. When we sleep, we remove the adenosine from our brain, so that when we wake up the next day, the sleep pressure is gone, and we can attack the day refreshed.
That’s all fine in theory, but of course we don’t get enough sleep, meaning that we don’t have the time to get rid of all the adenosine in our brain. Therefore, when we wake, that sleep pressure remains. This causes many of us to self-medicate in the form of caffeine, which stops adenosine from having its effect (although it doesn’t remove it from our brain) so that we can function. This becomes a self-perpetuating cycle: We consume more caffeine because we’re tired, and we’re tired because we don’t get enough sleep.
The caffeine-adenosine link was one of the first things I learned from my recent reading of Why We Sleep by Matthew Walker, founder of the Center for Human Sleep Science, and a professor of neuroscience at the University of California, Berkeley. The book is the most recent in a long line of “sleep self-help” bestsellers, including Night School, The Sleep Revolution, and Sleep: The Myth of 8 Hours. The popularity of these books tells a story in itself; adults know they need more sleep, a fact constantly reinforced by these book sales, and yet they don’t. So why is this?
Humans Are the Only Animals That Skip Sleep
Well, as Shona Halson, a leading expert on sleep in sport recently wrote, change is difficult, and we often believe the effort required to make a change isn’t worth it. The addictive nature of social media means we can’t resist checking our devices before bed, and before we know it, half an hour has passed. Similarly, the always-available entertainment on Netflix means that we want just one more episode before we go to bed, and the next thing we know we’ve binge-watched four hours and are facing another night of insufficient sleep.All animals sleep, but humans are the only ones that elect to shorten or avoid this behavior. Click To Tweet
Here’s another interesting fact from the book for you: all animals sleep, and yet humans are the only ones who routinely elect to shorten or avoid this behavior. It says a lot about human nature that we think we can overcome or simply ignore our hardwired biological need to meet our minimum requirement of sleep. Another fact from the book is that after a poor night’s sleep, the brain will never get back all the sleep it has lost, even if there is somewhat of a sleep rebound effect the following night. Routinely skipping out on a sufficient amount of sleep represents the loss of an opportunity for recovery that you will never get back.
A Breakdown of the Book
Of all the books on sleep I’ve come across, this is perhaps the one that best explores the science underpinning our need for sleep. The book contains chapters on how sleep enhances learning, and how a lack of sleep drives a number of health issues, including Alzheimer’s, cancer, and Type 2 diabetes. There is also a whole section dedicated to dreams, and what their purpose may be. For me, the key takeaway when it comes to the science is this: Sleep is so important to humans that, through evolution, we’ve found it best to spend around eight hours a day doing it—even when our risk of being attacked is much higher—rather than “evolve” our way out of needing sleep.
The book is split into four main sections, each comprised of three to five chapters. The first section deals with what sleep is, how it evolved, and how it works. This section was perhaps the most interesting for me, because it covered aspects I hadn’t come across before. Typically, I approach sleep from a sports performance perspective, as opposed to an evolutionary and biological aspect, so having this information at hand is really useful.
The second part of the book explores why we should sleep. Personally, a lot of this was old news to me, as it focused on the well-established health issues that can occur due to lack of sleep. The most interesting chapter in this section dealt with how sleep can affect the brain, especially learning and creativity. Both of these are crucial not just for athletes, but also coaches, who often have to utilize their creativity to effectively solve problems.Sufficient sleep can help an athlete emotionally recover from the setback of poor performance. Click To Tweet
The third part focused on dreaming, which was also interesting. A particular standout fact for me was the section on how sleep allows us to emotionally “deal with” stressors that have occurred during the day, resolving them and allowing us to move on. Again, this has a huge carryover into sport, where athletes can often dwell on poor performance, to the extent that it can have a lasting effect on them. Getting sufficient sleep can therefore aid in the process of the athlete recovering from such setbacks.
Finally, the last section looks at how we, and society in general, can sleep better. From a sporting perspective, the main thing appears to be avoiding early morning practices, especially with teenagers—they have a delayed circadian rhythm, and so getting up early can stunt their development.
A Deeper Look at Sleep Requirements
Overall, I’d recommend this book if you wish to know more about sleep. It’s far more general than Nick Littlehales’ book, which focuses on improving your own sleep. Instead, this book is a more generalized exploration of what sleep and its associated dream states are, what functions they play, and the societal and personal issues associated with a lack of sleep. As such, it’s also a deeper, perhaps more scientific look (similar to Wiseman’s Night School) at our requirement for sleep.Athletes aren’t the only ones impacted by poor sleep—coaches are too. Click To Tweet
This can be as much of a wake-up call for coaches as it can for athletes. Being under-slept leads to poorer decisions, which can reduce athlete performance, and can also impact your moods, making interactions with your athletes difficult. Quite often, coaches focus on improving their athlete’s performance—perhaps it’s time they focused on their own.
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