What are the best sleep hacks? What's the difference between deep sleep and REM? Which supplements support better sleep? These are just a few of the common questions people ask about sleep.



In this blog post, I'll do my best to provide you the answers to these questions and many others.





What are the phases of sleep?



Your body has an internal clock, which, when it's working well, determines the ebbs and flows of hormones and neurotransmitters, manages many of your body's systems, and guides you to sleep, wake up, nap, and move. Your internal clock is found in the suprachiasmatic nucleus (SCN).



Your environment also affects your circadian rhythm. External influences on your circadian rhythm are called Zeitbergers. Light is the most powerful Zeitberger, but diet, exercise, and supplementation also influence the SCN.



Messing with your circadian rhythm can have catastrophic effects on your health. For example:



Heart attack rates jump 25% the Monday after the clocks change to Daylight Savings Time.



That single-hour shift in your schedule does a lot of damage. It makes you wonder why we even mess with Daylight Savings Time anymore.



When your circadian rhythm is normal, you cycle through three phases each night.



Light sleep: During light sleep, you’re semi-conscious. You’re aware of your environment but only respond to something unexpected, such as the creaking of a door or your spouse whispering seductively in your ear. You have enough awareness to make sense of what’s happening but are asleep enough that you're often unmotivated to move unless you sense a threat, or you're a newlywed.



When you're under a substantial amount of stress, you can spend most of your night in this phase, and miss out on the benefits of the next two phases. Under normal circumstances, you remain in this phase for 10-30 minutes and then transition to deep sleep.



Deep sleep: This phase supports your body's growth and repair. Growth hormone peaks during deep sleep, which supports tissue repair and fat metabolism.



Rapid Eye Movement (REM): REM supports your brain's growth and repair. Your vibrant, funny, terrifying, exciting, and disturbing dreams occur during REM, as your brain tries to make sense of what's been on your mind, and consolidate information into memories.



REM makes up 20-25% of your total sleep time but varies throughout the seasons. The average person gets about 16% more REM in the winter than in the middle of the summer.



Your brain gets "washed" in cerebral fluid to help remove toxins, and neurogenesis, or the growth of new brain cells, increases. Chronic sleep deprivation limits your body's ability to generate new brain cells.



Oh, and one last bit of interesting trivia: Penile erection and clitoral swelling occur during REM as well. For guys, lack of a morning erection is a sign of low testosterone or insufficient REM sleep.



I wanted to highlight that point because I work with a lot of 40+-year-old men. When they notice their libido is low or it's been a long time since they had a morning erection, they often ask about testosterone boosters or hormone therapy. Often, what they need is sufficient, consistent sleep.



How much sleep do you need?



The following table, based on recommendations by the National Sleep Foundation, shows the amount of sleep each age group needs. Notice the significant amount needed by newborns to toddlers need. If parents want to develop healthy kids, they must help them get enough sleep every night.



GroupAgesIdeal SleepOlder Adult65+7-8Adult18-647-9Teenager14-178-10School Age6-139-11Preschool3-510-13Toddler1-211-14Infant4-11 months12-15Newborn0-3 months14-17



How does sleep affect your hormones?



The following table outlines what happens with your hormones and neurotransmitters at night.



Hormone / NeurotransmitterEffect From SleepGrowth HormoneHighest secretion of 24-hour cycle occurs during deep sleep, and is secreted in pulses with each cycle back into...