Unlocking Rem Sleep: Ben Greenfield's Guide To Enhancing Sleep Quality

Ben Greenfield is a personal trainer, biohacker, speaker, and performance coach. He uses the Oura Ring to track his Sleep, Activity, and Readiness stats. He focuses on his sleep stages and has found that taking an antihistamine before bed completely destroys his deep sleep levels. Greenfield also takes a deep dive into his Readiness metrics by leveraging the Oura web application to explore how his stats are related. He uses his Readiness score to plan his workout load for the week. Greenfield has found that when he pays attention to deep breathing patterns and deep belly breathing during the day, he can see a direct correlation between a drop in his respiratory rate and an increase in his sleep efficiency. He chose the Oura Ring because of its extremely high accuracy of sleep data and the ability to turn off the signal so he's not bombarding his body with a Wi-Fi or Bluetooth signal.

Avoid caffeine, theobromine and theophylline before bed

Caffeine is a stimulant that can interfere with your sleep. It blocks the production of melatonin, the hormone that regulates the sleep-wake cycle. Caffeine has a half-life of about 5-6 hours, which means that it takes about 24 hours for it to be completely eliminated from your system. So, if you have a cup of coffee at 8 am, half of the caffeine will still be in your system at 2 pm, and a quarter will remain at 8 pm. This is why it's recommended to avoid caffeine after noon if you want to get a good night's sleep.

Theobromine and theophylline are similar to caffeine in their chemical structure and their stimulating effects. They are found in cacao and kola nut, which are often consumed in the evening as comfort foods or drinks. Theobromine has a half-life of about 6-10 hours, and theophylline has a half-life of about 8 hours. This means that they can stay in your system for a long time and interfere with your sleep if consumed in the evening. So, it is recommended to avoid consuming cacao and kola nut products 6-10 hours before bedtime to get a good night's sleep.

• Avoid consuming coffee, tea, energy drinks, guarana, and maté after noon.
• Avoid consuming cacao and kola nut products after 3-4 pm, or at least 6-10 hours before bedtime.
• Check the labels of your food and drinks for these ingredients, as they may be present in unexpected places.
• If you crave something sweet or comforting in the evening, opt for herbal tea, decaffeinated cocoa, or a non-caffeinated beverage.
• Be mindful of hidden sources of caffeine, such as chocolate, some pain relievers, and energy drinks.
• If you enjoy a cup of coffee or tea in the afternoon, consider switching to decaffeinated versions.
• Create a bedtime routine that helps you wind down and relax, such as reading a book, listening to soothing music, or taking a warm bath.

Limit alcohol consumption

Alcohol is a sedative, and while it may help you feel sleepy, it can cause fragmented sleep, insomnia, or more serious sleep issues. Alcohol negatively affects sleep stages 3 and 4 (deep sleep) through adenosine blockade, but it also increases sleep latency (the time it takes you to fall asleep).

As alcohol starts to metabolize, the sedative effect wears off, and you may not sleep very deeply, or for very long, on and off throughout the night. That’s because as alcohol starts to metabolize, the sedative effect wears off.

Additionally, the effects on REM sleep seem to be milder.

The best way to avoid these issues is to limit alcohol consumption to two doses maximum if you are male and one dose if you are female. Enjoy your last glass of alcohol no later than 90 minutes before going to sleep.

Avoid tyramine-rich foods

Tyramine is an amino acid that increases the production of noradrenaline, which boosts brain activity and keeps you awake.

Tyramine is found in the following foods, so it might be wise to avoid or reduce their intake at dinner:

• Bacon
• Cheese
• Chocolate
• Eggplant
• Potato
• Sauerkraut
• Sausage
• Spinach
• Tomato
• Wine

Exercise daily

Regular daily exercise (20–30 minutes per day) has been shown to balance circadian rhythm and significantly improve sleep quality. Numerous randomised controlled trials have confirmed that exercise has multiple positive effects on sleep. These include better sleep quality, sleep onset latency, total sleep time, sleep efficiency, and lowered severity of insomnia.

On the other hand, low levels of physical activity are related to a greater prevalence of insomnia. According to a large meta-analysis conducted in 2018, exercise interventions may alleviate symptoms in people with insomnia without the use of hypnotics. A vigorous strength training program has been shown to increase deep sleep probably due to the fact that the body needs more repair time, which is occurring mostly in deep sleep. Overall resistance training improves all aspects of sleep.

The timing of exercise is important for sleep quality. Exercise earlier in the day may improve the quality of nocturnal sleep owing to the fact that exercise stimulates the sympathetic nervous system. To improve sleep quality, enhancing parasympathetic activity by allowing time for the stimulation of the sympathetic nervous system to diminish and allowing enough time for melatonin secretion to begin. The authors of this particular study, published in 2015, state that high-intensity exercise in the evening should be avoided. This means that you should not train too close to bed time.

However, according to one study conducted in 2014, the authors found that exercise an hour and a half before bedtime was associated with increased deep sleep and decreased REM sleep in healthy young adults. Especially individuals with greater self-perceived exertion during exercise had decreased light sleep and increased deep sleep compared to those with a lower level of exhaustion. That is something I have also noticed: the more vigorous my training, the more I get deep sleep and less REM sleep. But if I go totally overboard and simply train too much, also deep sleep begins to suffer. This has been seen in the research with overreaching and/or overtraining.

To summarize all the research on exercise and sleep:

• Exercise regularly (both aerobic and anaerobic exercise).
• Don’t exercise very close to bedtime (minimum of 1–2 hours before going into sleep or even more).
• Exercise with enough self-perceived exertion to stimulate more deep sleep.
• Practice regular resistance training for more deep sleep and growth hormone release.

Optimise your bedroom temperature

The body's core temperature naturally fluctuates during the day, reaching its highest point in the late afternoon and then beginning to cool down. Lowering the body temperature also helps to trigger melatonin secretion in the evening.

According to the National Sleep Foundation, the best temperature for sleep is approximately 60–67°F (15–19°C). Temperatures over 71°F (24°C) are likely to cause impaired sleep quality, and this is also true for a too-cold environment (53°F/12°C or below).

Sleeping in too hot a bedroom particularly affects REM sleep, but can also diminish deep sleep.

• Keep a small window open during the night to get cooler air into the bedroom.
• Take a cold shower or ice bath 2 hours before going to sleep.
• Use an air-to-air pump to keep the bedroom air at an optimal temperature.
• Use a cooling sleep system like Chilipad.
• Use breathable blankets, pillows, and sheets.
• Try sleeping naked (might not suit everybody).
• Keep your extremities warm to help dilate blood vessels, which allows better redistribution of heat throughout the body.
• If you don’t have access to a sauna and cold pool setup, take a hot-cold contrast shower sometime in the hours before bed: five to ten rounds of 10 seconds hot, 20 seconds cold.

Frequently asked questions