Exercise and nutrition are widely recognized as the pillars of health. However, sleep is often overlooked as a central health component. Sleep is vital to well-being, mood, and longevity—yet for decades our society has robbed itself of the rest our bodies so desperately need. As a society, we are beginning to broach the conversation about sleep, but we have a long way to go.
Each pillar of health plays a unique and complementary role in our health and homeostasis, so sleep, nutrition and exercise are inextricably linked to one another. For instance, if we are sleep deprived, we make poor food choices, our athletic performance and hand-eye coordination suffer and our mood is compromised. Sleep is a critical piece of any high performer’s routine—the ultimate recovery that repairs our bodies and brains from the day that just transpired and prepares us for what tomorrow may hold.
How and why sleep is so restorative
We have many theories as to why we sleep. One prominent view is the restoration hypothesis. During sleep, necessary restoration of body and brain tissue takes place. For instance, human growth hormone, responsible for muscle and bone repair, is released by the pituitary gland.1 Also at night, cortisol, the stress hormone, decreases dramatically, allowing our minds and bodies to naturally relax.2
In addition to the release of hormones associated with rest and recovery of the brain and body, there are other processes that happen in a circadian (circular) fashion, ebbing and flowing around a 24-hour clock. For instance, during sleep, body temperature, blood pressure and heart rate dip to their lowest points in the 24-hour cycle. This drop, particularly in blood pressure, is critical for maintaining a healthy blood pressure and lowering our risk of adverse cardiovascular events. The better sleep you get, the more enhanced your ability is to recover muscularly and lower your risk for health conditions.
Sleep and performance: How much do we really need to succeed?
Sleep’s importance is most pronounced when we go without rest. In a short period of time under conditions of shortened sleep, our mood deteriorates toward negative states (like stress and anxiety), and we exhibit signs of inflammation (such as higher levels of C-reactive protein and cortisol). These signs of inflammation cause your heart rate to rise and your nervous system to kick into high gear, all of which dampen our ability to excel at work or at the gym.
Research with elite rowers who cut their sleep time short reported more negative emotion and lower overall recovery ratings. However, when the same athletes added more sleep to their schedule they demonstrated healthy mood states and improved rates of recovery and performance.3 In other research, college-level weightlifters’ performance following 24 hours of sleep restriction showed the sleep deprived athletes reported more fatigue, less vigor, and more mood disturbance.4
These studies clearly demonstrate the detriment to health, mood, and performance imposed by insufficient sleep. Why is it that we continue in the face of this evidence to resist rest? Most experts agree between seven and eight hours of sleep at night is optimal for rest and recovery, yet each of us has a magic number in this range that is optimal for our daytime performance. It should also be noted that endurance athletes report – and perhaps need – more sleep, so individuals with intensive training programs may actually require between eight and nine hours of sleep for peak performance.
Sleep, nutrition, and performance
Sleep works in tandem with other health behaviors. For instance, insufficient sleep can result in physiological changes to how we metabolize and synthesize foods and lead us to perform poorly due to less vigor, intensity, and efficiency. Research also has examined the best foods for sleep. These findings suggest avoiding foods high in fat close to bedtime as they may negatively influence sleep.5 Research suggests that consuming foods with tryptophan, such as turkey or pumpkin seeds, or trying valerian, as an herbal supplement or tea, may improve sleep quality.5
The timing of our meal consumption is also important. A meal timed too close to bedtime may limit your ability to fall asleep, whereas a meal approximately two hours before bedtime is advised so as to nourish your recovery, but not hinder your sleep. Hence, exercise, nutrition, and sleep truly go hand in hand, where one impacts the other.
As a society, we are finally warming to the idea that the “I’ll sleep when I’m dead” philosophy counters strong, scientific evidence that sleep is an expedient route to health and your potential. In my career, I conduct research on the link between sleep and performance and develop strategies to help win individuals, communities, and cultures to the idea that rest is just as important, if not more so, than other domains of health. My vision is that one day we may elevate rest and recovery to a level of prioritization that positions a ritual of sufficient rest as a vital ingredient to health, wellbeing, and longevity as the undeniable and true pillar of health.
1 Takahashi, Kipnis, & Daughaday (1969) https://www.jci.org/articles/view/105893
2 Chokroverty, S. (1994) Sleep Disorders Medicine: Basic Science, Technical Considerations, and Clinical Aspects. Burlington: Elsevier Press.
3 Kolling et al (2016). https://www.ncbi.nlm.nih.gov/pubmed/26730643
4 Blumbert et al (2007) https://www.ncbi.nlm.nih.gov/pubmed/18076267/
5 Halson (2014) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4008810/