As part of our Biohacking Masterclass Series, we will explore a number of different techniques and practices to improve your daily performance. This series will range from obvious subjects like exercise and nutrition to fringe subjects like breathing techniques and sleep hygiene.
“Sleep is the greatest legal performance enhancing drug that most people are probably neglecting” - Dr. Matt Walker, Author of Why We Sleep
The performance changes aren’t limited to the realm of competitive athletes either. Whether you’re preparing for a championship game or presenting at a big meeting, sleep is arguably the most valuable tool at your disposal.
Study after study has shown that chronic sleep deprivation has many of the same health effects as behaviors like smoking. In modern life, most people have yet to understand the implications of both good and bad sleep hygiene even though it is as critical (if not more so) than diet and exercise. If evolution did not eliminate something that steals away a third of our life, there must be a reason, right?
Fortunately, researchers are beginning to shine a light on the myriad of restorative processes that occur every time our head hits the pillow. In the brain alone, sleep reinforces our ability to learn new skills, memorize concepts, improve our decision making, reinvigorate our emotional circuits, and dream up new ways to change the world. In the body, sleep accomplishes a similar number of astonishing feats. From normalizing metabolic activity and jump-starting physical recovery to arming our immune system and preventing malignancies, sleep does it all.
As a competitive athlete or working professional, there is not an area of life that proper sleep does not enhance. Of special concern for individuals with heavy training loads, sleep is responsible for that boost of growth hormone that takes your physical performance up a notch with more lean body mass, greater force production, and motor skill coordination. If your performance is more mental than physical, researchers have shown that certain stages of sleep enable mastery of newly learned skills overnight.
Before we embark on the journey of ‘hacking’ our sleep, it’s helpful to get a basic idea of how sleep actually works. If you’re only interested in the actionable bullet points we’ve provided, skip the following section. Otherwise, continue on.
Broadly, each night of sleep is separated into two distinct categories: NREM and REM. Early sleep researchers broke the four stages of NREM (Non-REM) sleep into an exciting 1, 2, 3, & 4, where 1 & 2 are light sleep and 3 & 4 are deep sleep (Slow wave sleep, SWS). Because of the eye’s darting activity in the fifth stage, these researchers called this portion REM, for rapid eye movement. The tradeoff between REM and NREM sleep stages goes in cycles of approximately 90 minutes. Generally, this cycle happens in the following pattern: wake, NREM stage 1, NREM stage 2, NREM stages 3 & 4, REM, and often beginning the cycle with stage 1 or 2 NREM again.
Most people will recognize REM as the dreaming stage of sleep. This stage generally functions to reinforce old neural connections and strengthen new connections in the brain (i.e. this stage is relevant to learning and integrating newfound knowledge into your brain for later use in problem solving, critical reasoning, and more). Cycles of REM typically lengthen as the night progresses, while the inverse happens with deep NREM stages. This pattern is tied to your circadian rhythm as well. *Note*: This is of critical importance when you consider your sleep and wake times relative to your established circadian rhythm. If you normally go to bed at 11:00 and wake at 7:00, going to bed one night at 1:00 will disproportionately affect your body’s deep NREM sleep stages (detailed further below). Conversely, waking up at 5:00 after an 11:00 bedtime will disproportionately affect your REM stages, limiting your brain’s ability to process information into your existing network of knowledge.
Stages 3 & 4 of NREM sleep are collectively also called slow wave sleep (SWS). As mentioned above, these stages tend to be longer in the early hours of sleep. From a learning perspective, these stages of sleep are important for fact-based memory. In studies, researchers determined that these stages were responsible for transferring new knowledge from short-term storage to long-term storage. From a physical standpoint, the activity during healthy SWS cycles includes regulating the proper production of human growth hormone (hGH). In some studies, researchers concluded that 70% of all growth hormone pulses occurred during the deep stages of NREM sleep.
In light NREM sleep, we are limiting the scope of the article to stage 2. In this stage, brain waves are characterized by periodic ‘sleep spindles’. The brain’s activity in stage 2 NREM facilitates learning of non-factual information, such as the acquisition of new motor skills (i.e. learning the physical act of something, such as route running or piano). When you spend a considerable amount of the day practicing a specific task, this stage of NREM sleep will enable your brain to translate robotic, conscious movement into something fluid and seemingly second-nature.
I want more growth hormone, can I ‘hack’ my way into more SWS/stage 3 NREM specifically? REM?
The best way to get more of any specific stage is to get more sleep overall and to become a professional in the sleep hygiene department. We’ve put together a list of actionable tips for you to take your sleep game to the next level.
- Our personal favorite: using the right lighting for your evening routine. So much of ‘biohacking’ is really just taking your body back to the routines developed over the thousands and thousands of years in our evolutionary history. Simply, this means eliminating white, blue, and green light at dusk. We’ve got a full article written here. This straightforward practice helped us increase our REM, SWS, and overall sleep efficiency dramatically.
- Exercise in some capacity every day. From stressing your autonomic nervous system for better parasympathetic/sympathetic balance to increasing deep sleep, exercise will improve your body’s innate restorative processes. Aim to avoid aerobic activity too late in the evening. (Some experts suggest limiting exercise 2-3 hours before bed.)
- Create a true sleeping environment. A bedroom is for two things that start with S and sleeping is one of them. Eliminate the use of electronics, and remove as many unnecessary electronics as possible (that means pretty much all of them with the exception of an alarm if you need it).
- Make it dark. In line with removing electronics, eliminating all unnatural light is key. Blackout shades will make a huge difference in your sleep efficiency if you’re not using them already.
- Make it cold. The optimal sleeping temperature is between 60-67 degrees, and it’s far better to be on the cold side than the warm side. Drop that temp and bring out another blanket if you need to. You need to drop your core body temp 1 degree Celsius or 2-3 degrees Fahrenheit. Again, what happens during the day? Outside temperature rises during waking hours and falls at night - our body relies on these cues.
- Use saunas and heat baths to your advantage. Taking a long hot bath before bed dilates the blood vessels in your extremities in an effort to lower core body temp during the bath. When you get out, all of that heat will dissipate and assists in dropping your core temp for bedtime. Dry saunas have also been shown to increase hGH production.
- Take advantage of power naps. Sleeping for as little as 20 minutes can get you major performance gains, as long as some of that sleep contains stage 2, light NREM sleep (sleep spindles win again). In research settings, such naps resulted in improved mental and physical output (ex: 20% learning advantage over control in one study). Limit these naps to before 3pm and avoid naps in the 30-90 minute range. Fragmenting sleep cycles can do more harm than good, so if you plan on taking a longer nap, allow yourself to sleep for a full 90 minutes.
- Get daytime light exposure. Your body relies on a couple of internal clocks, one of which is your light-driven circadian rhythm. Setting both ends of your schedule will reinforce your body’s sleep habits. We’ve found that a 10,000 lux light right as you wake up will knock off any grogginess and will enable your body to set that sleep-wake schedule.
- Avoid chemically-induced sleep. Alcohol, THC, and many OTC sleep meds reduce the quality of your sleep (Objective quality, not perceived quality). Obviously, talk to your physician if you’re having trouble sleeping. We are not your physician.
If you’re feeling particularly curious about your sleep and would like to expand your knowledge further, we’ve found anything by Dr. Matt Walker to be thought-provoking and coherently written. His book Why We Sleep is a tremendous resource, and many of our referenced studies came from his lab.
Takahashi Y, Kipnis DM, Daughaday WH. Growth hormone secretion during sleep. J Clin Invest. 1968;47(9)
Van Cauter E, Plat L. Physiology of growth hormone secretion during sleep. J Pediatr. 1996;128
Laura Redwine, Richard L. Hauger, J. Christian Gillin, Michael Irwin, Effects of Sleep and Sleep Deprivation on Interleukin-6, Growth Hormone, Cortisol, and Melatonin Levels in Humans, The Journal of Clinical Endocrinology & Metabolism, Volume 85, Issue 10, 1 October 2000, Pages 3597–3603
Walker MP. The role of slow-wave sleep in memory processing. Journal of Clinical Sleep Medicine 2009: 5: S20-26
Walker MP & van der Helm E, Overnight Therapy? The role of sleep in emotional brain processing. Psychological Bulletin 2009: 135: 731-748.
Walker MP. Cognitive consequences of sleep and sleep loss. Sleep Med, 2008: 9, S29-34.
Walker MP. Sleep-dependent memory processing. Harvard Review of Psychiatry. 2008: 16(5): 287-298.
Walker MP, Stickgold R. Sleep-dependent learning and memory consolidation. Neuron 2004:44:121–133.
Walker MP, Brakefield T, Hobson JA, Stickgold R. Sleep and the time course of motor skill learning. Learning & Memory 2003:10(4):275-284.