If you want to be your best – in literally anything – optimizing your sleep is your number one performance enhancer. There is not one major organ within the body, or process within the brain, that isn’t enhanced by sleep (or impaired when you don’t get enough). Sleep makes you live longer. It enhances your memory and makes you more creative. It makes you look more attractive. It keeps you slim and lowers food cravings. Sleep improves both cognitive and motor learning. It protects you from cancer and dementia. It wards off colds and the flu. It lowers your risk of heart attacks, stroke, and diabetes. You’ll feel happier, less depressed, and less anxious. In athletes, sleep improves physical performance and reduces the risk of injury.
These conclusions come from over 17,000 carefully examined scientific reports to date. I highlight some of the most interesting and useful facts for leaders in the sections below.
Learn More, Remember More
As a leader, how important is it for you to learn new information and retain it?
Sleep before learning refreshes our ability to make new memories. The brain constantly takes in new information throughout the day and fills our hippocampus (the part of our brain that temporarily stores information) which has a limited capacity, much like a USB memory stick. Sleep, specifically the sleep spindles (short, powerful bursts of electrical activity) of stage 2 NREM sleep, clears out the fact-based memories from the hippocampus to a long-term secure vault in the brain (the cortex). This replenishes the available free space to absorb new information, with previous learning now more securely stored. Of note, it is in the late-morning hours between long periods of REM sleep that the concentration of light NREM-sleep spindles are especially rich. Sleeping six hours or less short-changes the brain of this learning restoration benefit.
Sleep after learning clicks the “save” button on these newly created memory files. But this occurs mostly during early-night sleep that is rich in deep NREM stages. The slow brainwaves of deep NREM serve as a courier service, transporting memory packets from a temporary storage hold (hippocampus) to a more secure, permanent home (the cortex). This extends to learning physical skills as well, with overnight motor-skill enhancement being directly related to the amount of stage 2 NREM sleep gotten, particularly in the last two hours of an eight-hour night of sleep.
Getting a full eight-hours rest is important to maximize the benefits of both early and late sleep stage cycles. Due to this uneven distribution of sleep cycles, going to bed late and getting up early impair health and performance in different ways.
The scary thing about not getting enough sleep is that you do not know how sleep-deprived you are when you are sleep-deprived. Participants in studies of sleep deprivation consistently underestimated their degree of performance disability. It is the equivalent of your intoxicated friend picking up his car keys and confidently telling you, “I am fine to drive home.” In fact, a study in Australia found that individuals awake for nineteen hours were as cognitively impaired as those legally drunk with a .08% blood alcohol level. So if you are up at 6AM, work a full day and join your colleagues on Friday for happy hour after work – and drink only water – by the time you drive home at 1AM you are as cognitively impaired in your ability to attend to the road and what is around you as a legally drunk driver.
Naps Are Fantastic, But Only If You Time Them Right
All humans have a genetically hardwired dip in alertness mid-afternoon (called the post-prandial alertness dip). This daily rhythm of life favors an afternoon nap. Back in the 1980s, Greece would have a siesta with businesses open from 9AM-1PM, closed from 1-5PM, then open again from 5-9PM. But as we approached the millennium there was pressure to abandon this practice. And the results were catastrophic.
Researchers from Harvard University’s School of Public Health looked at more than 23,000 Greek adults and focused on their cardiovascular outcomes across a six-year period as the siesta practice came to an end for many of them.
None of the individuals had a history of coronary heart disease or stroke at the start of the study. Those that abandoned regular siestas suffered a 37% increase in the risk of death from heart disease across the 6-year period relative to those who maintained regular daytime naps. The effect was especially strong in working men, increasing risk to well over 60%.
In small enclaves of Greece where siestas remain intact, such as the island of Ikaria, men are nearly four times as likely to reach the age of 90 as American males.
Naps improve performance too. Usain Bolt on many occasions has taken naps in the hours before breaking the world record, and before Olympic finals in which he won gold. Daytime naps contain enough sleep spindles in stage 2 of sleep to offer significant motor skill memory improvement, together with a restoring benefit on perceived energy and reduced muscle fatigue. … If naps can help win Olympic gold, what can they do for your afternoon performance?!?
Naps can’t “make up” for sleep that is lost. What is lost is lost. But they can improve performance and work better to prevent cognitive decline if taken before bouts of sleep deprivation. They are no substitute for a full eight hours of nightly sleep, but they are a performance enhancer.
So here is the key to napping right. Take either a 20-30 minute “power nap” or a longer 90-minute nap, but not in between. Take it after noon (to coordinate with you post-prandial alertness dip) but before 2-3PM so as to not interfere with your ability to fall asleep later that night.
- 20-30 minutes is enough time to get improved alertness, enhanced performance, and better mood by keeping you in the light stage of NREM sleep
- If you nap 30-60 minutes, you are likely to fall into a deep sleep and awaken groggy with a sleep hangover and less alert than before.
- Nap for 90-minutes and enjoy the benefits of one full sleep cycle, from light sleep to deep sleep and back to light again, awakening refreshed. Naps of this length boost memory and creativity.
Sleep in the Workplace
There is a mistaken belief that time on task equates with task completion and productivity. Key performance indicators (KPIs) such as net revenue and goal accomplishment are determined by employee traits such as creativity, intelligence, motivation, effort, efficiency, effectiveness when working in groups, emotional stability, sociability, and honesty. All of these are negatively impacted by insufficient sleep.
Sleep-deprived individuals generate fewer and less accurate solutions to work-relevant problems they are challenged with. Individuals like their job less when sleep deprived. They are also more unethical.
The frontal lobe, which is critical for self-control, is taken offline by a lack of sleep. This contributes to emotional instability and the expression of strong emotions such as anger and rage, as well as the activation of the fight-or-flight response. As a result, employees who sleep six hours or less are significantly more deviant and more likely to lie the following day than those who get six hours or more. Under-slept employees are more likely to blame other people for their own mistakes and even take credit for other people’s successful work. Sleep loss contributes to social loafing. Individuals see an opportunity to slack off and hide behind the collective hard work of others. What might these types of behavior do to your organization’s reputation and/or productivity?
As a leader, sleep (and the lack of it) has unique effects on you. Differences in leadership performance fluctuate dramatically from one day to the next based on sleep. The size of that difference far exceeds the average difference from one individual leader to another. This means that “good” leadership may not be as stable a trait as we previously thought. And sleep quality may be more vital to your performance than you could ever have guessed.
Your sleep affects the quality of work of your subordinates. In an interesting study, in the days after a supervisor had slept poorly, the employees themselves (even if well-rested), became less engaged in their jobs throughout that day as a consequence. In this case, a leader’s poor sleep infects well-rested employees with work disengagement and reduced productivity. Under-slept managers and CEOs are less charismatic and have a harder time infusing their teams with inspiration and drive.
The sleep quality of your employees affects you as well. Even if you are well-rested, sleep-deprived employees will erroneously perceive you as being significantly less inspiring and charismatic than you truly are. And none of us want that!
So if you and your colleagues want to reach your highest potentials, you (and they) truly must sleep your way to the top.
Dr. Eddie O’Connor is a professional speaker and both clinical and sport psychologist, specializing in removing barriers to peak performance. He is a Fellow and Certified Mental Performance Consultant through the Association for Applied Sport Psychology, and a member of the United States Olympic Committee Sport Psychology Registry. Dr. Eddie has worked with youth, high school, collegiate, national and international, Junior Olympic and professional athletes and coaches, as well as performing artists and musicians. He is also the author and host of “The Psychology of Performance: How to Be Your Best in Life” by The Great Courses
Dr. Eddie highly recommends the book “Why We Sleep” by Matthew Walker, Ph.D. (2017, Scribner, New York), which was a source for this article.