Sleep Basics: Sleep Hygiene

Studies estimate that around 30% of adults have experienced one or more symptoms of insomnia including difficulty falling asleep (sleep initiation), difficulty staying asleep (sleep maintenance), or waking up too early (early-morning awakening) 1. That means that almost 1 in 3 American adults experience trouble with sleep, an incredible number

This post will be the first in a series of posts on sleep. In addition to providing evidence-based recommendations for improving sleep hygiene, I’ll review the more common sleep supplements (i.e. melatonin and valerian root) and discuss the types of prescription sleep medications.

Now, on to behaviors that promote and enhance sleep, known as sleep hygiene.

  1. Maintain regular sleep-wake cycles. Going to sleep much earlier than usual causes greater sleep latency (longer time to fall asleep), whereas going to bed much later than usual causes increases wakefulness in the latter part of the night. Your body has a natural sleep-wake rhythm, try to stick to it as much as possible.
  2. Minimize light exposure during sleep. We know that tablets, iPhones, anything with a backlit screen, and sunshine actually decrease melatonin production (a hormone that promotes sleep) and can shift your sleep-wake cycle. Basically, light promotes wakefulness and blocks sleep. Minimize it by turning off your iPhones, reading a real paperback book (no backlit kindles for you), and buying those blackout curtains you’ve always wanted.
  3. Avoid naps unless you’re in a situation where sufficient sleep cannot be obtained. Naps decrease the quality and increase the latency of sleep. The only justification for napping is if you’re unable to obtain sufficient sleep (i.e. you’re a long-haul airline pilot or a medical resident working a 24-hour shift). In that case, naps have been show to help mitigate the impact of sleep deprivation on mental performance.
  4. Moderate caffeine intake. Most sleep hygiene recommendations encourage people to limit their caffeine use overall, especially in the late afternoon and evening. Although logically you would expect decreasing caffeine would improve sleep, a study demonstrated that 100mg of caffeine (~ 1 cup of coffee) administered at bedtime had minimal effects of sleep. The take home? Keep your caffeine at around 300mg a day, don’t drink it all at night, and you’re probably okay. (Fun facts: 1) Caffeine is a potent blocker of adenosine receptors. Adenosine is produced throughout the course of a day and promotes sleep; caffeine blocks this promoting wakefulness.  2) Caffeine’s half life is 5 hours, meaning that that cup of coffee you drank this morning won’t be completely out of your system for almost 20 hours.)
  5. Limit alcohol for up to 6 hours before you go to sleep. Alcohol helps you go to sleep faster, but it makes the sleep you actually get less restorative by decreasing the amount of time you spend in REM. This effect has shown to persist for alcohol ingestion as much as 6 hours prior. Not a fun recommendation, but if sleep is your priority, limit the alcohol.
  6. Exercise because it’s good for you, but not right before bed. Exercise completed in the afternoon and early evening may increase the depth of your sleep, however exercise right before bed has been shown to prolong sleep latency. Exercise in the morning has not been shown to have an impact on sleep parameters.
  7. Take a hot bath before bedtime. Aside from providing relaxation for the mind, taking a warm bath prior to sleep can increase the depth of sleep. The mechanism may be due to the relationship between core-body temperature and the circadian rhythm. It’s thought that a steeper downward slope in core body temperature (i.e. cooling off after a hot bath) may aid in sleep promotion.

I hope this was informative! More information on evidence-based sleep hygiene can be found here and the caffeine content in most drinks here).