You Spend 1/3 Of Life Sleeping
With a busy life, you can be easily tempted to cut into that shuteye time to get more into your day. Many Americans do exactly that with only half of all them getting the recommended amount of sleep. (1)
While it seems like an easy way to get ahead, it comes at a cost. For starters, it costs the US an estimated $411 billion every year. (2) That’s more than the value of Walmart, Whole Foods, and every American car company combined.
So while a 4-hour sleep schedule is a worn like a badge of honor, it's almost certainly not the best long-term course and here’s why.
Mental Benefits of Sleep
Better Thinking - Consecutive sleep loss decreases mental performance to the same degree as a blood-alcohol level of 0.06 (2-3 drinks). (3)
Better Memory - Quality sleep increases memory by as much as 20%. (4)
Better Problem Solver - Problem solving performance can increase by as much as 40%. (5)
More Creative - One night of sleep loss causes innovative thinking to deteriorate significantly. (6)
More Positive - Sleep loss causes anxiety to increase and emotional stability to decrease. (7)
More Productive - Worse sleep quality lowers productivity the next day. (8)
Make Better Decisions - Sleep deprivation impairs ability to make rational decisions. (9)
More Ethical - Lack of sleep leads to high levels of cheating and unethical decisions. (10)
TL;DR
Sleep deprivation makes you a slower thinker, worse decision maker, less productive, less ethical, less creative, and a more stressful version of yourself.
Physical Benefits of Sleep
Be Stronger - Inadequate sleep significantly decreases strength and work capacity. (11)
Live Longer - Less than 4.5 hours and more than 8.5 hours increases chance of death by up to 15%. (12)
Decrease Obesity Risk - Sleep deprivation increases appetite and is linked to higher BMI (Body Mass Index). (13)
Decrease Heart Disease Risk - Under sleeping (<5 hours) and over sleeping (>9 hours) increases risk of heart disease by up to 33%. (14)
Decrease Alzheimer's Risk - One night of sleep loss increases beta amyloid, the Alzheimer’s protein. (15)
Decrease Diabetes Risk - Three nights of poor sleep associated with increased risk of diabetes, stroke, and heart attack. (16)
Decrease Injury Risk - Decreasing sleep time by 40 minutes increases workplace injury by 6%. (17)
TL;DR
Sleep deprivation decreases your strength and lifespan while it increases your chances of being diagnosed with disease or being injured.
How Much Sleep?
Sleep recommendations will be different depending on your age and your lifestyle. (18) For a general recommendation, multiple studies indicate that 7 hours is the optimal number to shoot for. Less than 5 hours and more than 9 increase your risk of mortality. (19)
3 Ways to Optimize Sleep
Block Blue Light - Blue light from screens significantly impacts sleep quality. Here are some free ways to avoid this and still use your devices: use Night Shift mode on your phone and install f.lux for your computer. (20)
Follow A Schedule - Irregular bedtime schedule decreases sleep quality. Go to bed at the same time every night to optimize sleep patterns. (21)
Black Out - Even if your eyes are closed, light will still suppress melatonin. Sleep masks are a cheap and easy way to block out light and significantly improve sleep quality. (22)
Conclusion
If a supplement existed that had all of sleep's benefits, you would buy it. The bad news is that no supplement exists. The good news is that sleep does and it’s free. Sleep 7-8 hours every night to be a significantly improved version of yourself.
Evidence
1. Gallup, Inc. "In U.S., 40% Get Less Than Recommended Amount of Sleep." Gallup.com. December 19, 2013.
2. "The Costs of Insufficient Sleep." RAND Corporation.
3. Barnes, Christopher M., and Christopher L. Drake. "Prioritizing Sleep Health." Perspectives on Psychological Science 10, no. 6 (2015): 733-37.
4. Potkin, Katya Trudeau, and William E. Bunney. "Sleep Improves Memory: The Effect of Sleep on Long Term Memory in Early Adolescence." PLoS ONE 7, no. 8 (2012).
5. Harvard Health Publishing. "Learning While You Sleep: Dream or Reality? - Harvard Health." Harvard Health Blog.
6. "One Night of Sleep Loss Impairs Innovative Thinking and Flexible Decision Making." Egyptian Journal of Medical Human Genetics. May 25, 2002.
7. "Cumulative Sleepiness, Mood Disturbance, and Psychomotor Vigilance Performance Decrements During a Week of Sleep Restricted to 4–5 Hours per Night." Sleep, 1997.
8. Glozier, Nicholas, Alexandra Martiniuk, George Patton, Rebecca Ivers, Qiang Li, Ian Hickie, Teresa Senserrick, Mark Woodward, Robyn Norton, and Mark Stevenson. "Short Sleep Duration in Prevalent and Persistent Psychological Distress in Young Adults: The DRIVE Study." Sleep 33, no. 9 (2010): 1139-145.
9. Lanaj, Klodiana. "Beginning the Workday Already Depleted? Consequences of Late-Night Smartphone Use and Sleep Quantity." Academy of Management Proceedings 2012, no. 1 (2012): 1.
10. Killgore, William D. S., Thomas J. Balkin, and Nancy J. Wesensten. "Impaired Decision Making following 49 H of Sleep Deprivation." Journal of Sleep Research 15, no. 1 (2006): 7-13.
11. Barnes, Christopher M., John Schaubroeck, Megan Huth, and Sonia Ghumman. "Lack of Sleep and Unethical Conduct." Organizational Behavior and Human Decision Processes 115, no. 2 (2011): 169-80.
12. Reilly, Thomas, and Mark Piercy. "The Effect of Partial Sleep Deprivation on Weight-lifting Performance." Ergonomics 37, no. 1 (1994): 107-15.
13. Kripke, D. F., L. Garfinkel, D. L. Wingard, M. R. Klauber, and M. R. Marler. "Mortality Associated with Sleep Duration and Insomnia." Advances in Pediatrics. February 2002.
14. Taheri, Shahrad, Ling Lin, Diane Austin, Terry Young, and Emmanuel Mignot. "Short Sleep Duration Is Associated with Reduced Leptin, Elevated Ghrelin, and Increased Body Mass Index." PLoS Medicine 1, no. 3 (2004)
15. Mistlberger, Ralph, and Brianne A. Kent. "Faculty of 1000 Evaluation for β-Amyloid Accumulation in the Human Brain after One Night of Sleep Deprivation." F1000 - Post-publication Peer Review of the Biomedical Literature, 2018.
16. Grandner, Michael A., Nicholas J. Jackson, Victoria M. Pak, and Philip R. Gehrman. "Sleep Disturbance Is Associated with Cardiovascular and Metabolic Disorders." Journal of Sleep Research 21, no. 4 (2011): 427-33.
17. Barnes, Christopher M., and David T. Wagner. "Changing to Daylight Saving Time Cuts into Sleep and Increases Workplace Injuries." Journal of Applied Psychology 94, no. 5 (2009): 1305-317.
18. "National Sleep Foundation Recommends New Sleep Times." National Sleep Foundation.
19. "Association of Sleep Duration with Mortality from Cardiovascular Disease and Other Causes for Japanese Men and Women: The JACC Study." Sleep, 2009.
20. Eyvazlou, Meysam, Esmaeil Zarei, Azin Rahimi, and Malek Abazari. "Association between Overuse of Mobile Phones on Quality of Sleep and General Health among Occupational Health and Safety Students." Chronobiology International 33, no. 3 (2016): 293-300.
21. Kang, Jiunn-Horng, and Shih-Ching Chen. "Effects of an Irregular Bedtime Schedule on Sleep Quality, Daytime Sleepiness, and Fatigue among University Students in Taiwan." BMC Public Health 9, no. 1 (2009).
22. Kang, Jiunn-Horng, and Shih-Ching Chen. "Effects of an Irregular Bedtime Schedule on Sleep Quality, Daytime Sleepiness, and Fatigue among University Students in Taiwan." BMC Public Health 9, no. 1 (2009).