Over 20 large-scale studies that have tracked millions of people over decades all point to the same conclusion: if we sleep well and enough, our cognitive abilities are significantly enhanced and our risk for diseases is substantially lower, resulting in a longer life.
What I used to believe: If I sleep less, I get more done.
What I know today (backed by science!): Sleep is the essence of sustained high performance, productivity, health, and happiness.
What you need to know about sleep
Your body goes through five stages of sleep each night, also known as a sleep cycle. Each sleep cycle lasts roughly 90 minutes and consists of both non-REM sleep (or NREM) during stages 1-4, and REM (short for Rapid Eye Movements) at the last stage. Ideally, the body will pass through four to five of these cycles each night, waking up at the end of the cycle, when sleep is lightest.
Stages 1-2 (NREM):
– Light sleep
- Muscles start relaxing
- Drop in body temperature
- Heart and breathing rates begin to slow
Stages 3-4 (NREM):
– Deep sleep
- Muscles fully relax
- Immune system strengthens
- Body repairs and regenerates
Stage 5 (REM):
– Active sleep
- Vivid dreams
- Irregular rapid eye movement
- Mental restoration (overall mood and long-term memory improves)
Why we need an average of 7.5 hours of sleep
We sleep in the above-mentioned rhythmical cycle. After we fall asleep, a standard sleep cycle takes us from light sleep into deep sleep and then back to light sleep before we move into REM. After the REM phase, our body awakens briefly and then the cycle is repeated.
To be fully rested and renewed in the morning, most people need 4-5 complete sleep cycles every night. One complete cycle lasts roughly 90 minutes. That’s why most people feel most productive and rested after sleeping for 7.5 hours (equals 5x 90 minutes sleep cycles). Your personal ideal sleep time might be longer or shorter depending on the exact duration of your individual sleep cycles.
Tip: If it’s hard for you to wake up chances are that you are in a deep sleep phase when your alarm rings. Try getting up 30 minutes earlier or later. There is an App called SleepCycle that solves this problem for you. This app tracks and analyzes your sleep, waking you up at the most perfect time.
Benefits of sleep
Sleep comes with many benefits for the mind and body. Sleep not only restores vitality, strength, and health but also sharpens the mind, improves our memory, and enhances our emotional intelligence. Not to mention, consistently sleeping well lowers our risk of some of the world’s deadliest diseases, including cancer, heart disease, and diabetes.
How to optimize sleep quality
– Use light to your advantage
- Why? Natural light keeps your internal clock on a healthy sleep-wake cycle. So let in the light first thing in the morning and avoid bright light (smartphones, laptops, TV) at night. Bright light at night prevents melatonin (the sleep hormone) production. If you have to use your smartphone at night make sure you use the night shift mode, which filters out the artificial blue light.
– Keep your bedroom temperature at about 65°F (18-19°C)
- Why? When we sleep our core temperature drops by 2°F/ 1°C. A temperature of 65°F (18-19°C) optimally supports this drop in body temperature.
– Take a warm bath or shower an hour or two before going to bed
- Why? Research has shown that it will help lower your core temperature, and that’s a natural sleep signal.
– Keep your internal clock set with a consistent sleep schedule
- Why? Going to bed and waking up at the same time each day sets the body’s “internal clock” to expect sleep at a certain time night after night. Try to stick as closely as possible to your routine on weekends to avoid a Monday morning sleep hangover. If this is not possible follow the next strategy.
– Performance-enhancing naps for 26 minutes anywhere between 1-4 pm
- Why? Back in the 1990s NASA recognized the importance of sleep and created a nap culture throughout the organization. They found that even short naps that are 26 minutes long increase alertness by 50% and increase performance on a task by 34%. Don’t nap longer -studies show that sleeping longer will leave you feeling sluggish, groggy, and more tired than before you closed your eyes.
– Invest in a high-quality mattress and an ergonomic pillow
- Why? If your average night’s sleep is eight hours (one-third of a day), you sleep for one-third of your life. If you live, say, 75 years, that’s 25 years of sleep. IT’S WORTH IT!
– Establish a calming pre-sleep routine
- Why? Pre-sleep routines help your body and mind to calm down at the end of the day. Reading, listening to music, journaling, meditating… Whatever you do make sure it helps you to relax into sleep.
Getting quality sleep is one of the best things you can do for your performance, productivity, energy, health, and happiness.
If there is just one thing you take away from this guide, I hope it’s this: Prioritizing your sleep is a necessity not a luxury when it comes to sustained high performance!