17 Articles and Some Notes on Sleep and Napping
As part of the experiment in making time, I want to do a little sleep hacking. Thing is, I needed to learn a few things about sleep first.
A little research
In order to get up to speed with some of the finer yet important details on sleep and napping, I did a little online research. The idea is that in order to get the most from life, training and recovery, a person needs to be well rested. My objective is to find a sleep strategy that allows me to get the most "bang for my buck" in terms of hours spent sleeping.
The following notes were taken while reading the articles linked at the bottom of the page. Keep in mind that these are from the internet and I did not do any background checks on the authors of the articles below. Some copying and pasting was employed.
Notes on Sleep
- Sleep is anabolic.
- Lack of sleep will stunt regenerative processes and the immune system, leading to a gradual lack of recovery, performance decrement and eventually over-training syndrome, loss in training gains, chronic fatigue and lots of other bad stuff for triathletes.
Sleep can be divided into five distinct stages: stages 1-4 consist of non-rapid-eye-movement sleep and account from 66-80% of sleep time; during a normal night of sleep, these are usually followed by the rapid-eye-movement (REM) stage of sleeping (stage 5):
- "The gateway to sleep", this stage can last up to 10 minutes. It is short lived and has theta waves, which are thought to help reduce mental fatigue by restoring sodium/potassium balances in the brain.
- Lasting anywhere from 10-20 minutes, or 45-55% of total sleep depending on where you read, in stage two you lose awareness to external stimuli.
- The beginning of slow wave sleep (SWS), which includes stage 4; 3-8% of total sleep time. Here we start to see delta waves, with GH secretion and dreamless sleep.
- Slow wave sleep; 10-15% of total sleep time. Delta waves, GH secretion and dreamless sleep.
- REM sleep, predominant in the final third of a sleep period. Dreaming occurs here.
- Humans sleep in ~90 minute cycles of the non-rem and rem phases, although age and the amount and quality of sleep on previous nights can alter this pattern.
- [Dr. Claudio Stampi's] research also showed that afternoon siestas were chock-full of slow-wave sleep, the type that appears to be most important for recharging the body... The key to napping efficiently, Stampi says, is to get in phase and ride these waves of sleepiness and alertness, so no time is wasted merely trying to get to sleep.
- Non-REM sleep is an anabolic state marked by physiological processes of growth and rejuvenation of the organism's immune, nervous, muscular, and skeletal systems.
- the body seems to want its slow-wave fix first, and racks up most of the slow-wave quota in the first three hours. If you slash eight hours of sleep to four and your body has to triage, you retain 95 percent of the slow-wave sleep while ditching large chunks of REM and stage-two sleep.
- REM sleep appears to help with the consolidation of spatial (recording information about one's environment and its spatial orientation) and procedural memory (long-term memory of skills and procedures, e.g. riding a bike), while slow-wave sleep helps with the consolidation of declarative memories.
- A decline in sleep quality and quantity has been observed to cause in increase in adrenal hormone cortisol and a decrease in Growth Hormone.
- A decline in slow wave sleep from early adulthood to mid-life was parallelled by a major decline in GH secretion.
- As little as 20 hours of sleep deprivation can impair mental performance.
- A 20 percent overnight improvement in learning a motor skill is largely traceable to a late stage of sleep that some early risers might be missing.
- Accumulative sleep deprivation has been shown to reduce cardiovascular performance by 11%.
- Mental functioning decreases nearly twice as rapidly as physical performance.
- It would appear that sleep loss does not affect physical performance in the same manner as it does mental, (I assume that it affects physical recovery).
- Minimal levels of sleep loss result in an increased perception of effort.
- Sleep is a period for brain and nerve cell detoxification and immune system stimulation.
- Light has the greatest effects on setting the daily timing of melatonin release.
- If you want to wake up earlier, expose yourself to bright light earlier.
- Melatonin is the hormone in the brain that initiates sleep and it stimulates immune system cells, increasing their function in all areas of the body.
- Melatonin functions as an anti-oxidant in cells and in general is a defender against oxidation.
- Optimising melatonin release: low light (avoid bright light) two hours before bedtime - it is the intensity of light, not the duration of exposure, that has the suppressive effects on melatonin release.
- Optimum Sleep Environment
- Dark (see notes on melatonin)
- Comfortable (you may feel comfortable in bed, but can you be more comfortable? A better pillow, softer sheets, more room to flip around etc.)
- Proper Lighting (see notes on melatonin)
- Cool temperatures:
Your body temperature tracks your circadian rhythm, so as night begins, your body temp falls and it reaches a minimum right after you go to bed. If you are in an environment where you can't lose body heat, for instance if it's hot and humid, you won't sleep well.
- Alcohol causes disrupted and fragmented sleep.
- Establish a consistent sleep pattern. Changing your schedule for more than two days or sleeping more than an hour longer on weekends disrupts your body’s biological clock.
Notes on Napping
- Chris Carmichael, says that "naps were critical in [Lance Armstrong's] overall training plan."
- a midday snooze reverses information overload.
- A good powernap to reduce mental fatigue during the day lasts about 20 minutes.
- Studies found that longer 1-hour naps contained more than four times as much deep, or slow wave sleep and rapid eye movement (REM) sleep than the half-hour naps.
- For muscle recovery to occur during a nap, one needs to hit slow wave sleep; can be anywhere from 50 to 90 minutes (a whole cycle). Waking in the middle of this type of nap may result in Sleep Inertia.
Articles from around the net
- "Power Nap" Prevents Burnout; Morning Sleep Perfects a Skill
An interesting look at short naps versus longer naps and sleeping, and it's effects on preventing burnout and increasing motor skills.
- Sleep From Wikipedia
A pretty damn comprehensive overview of sleep, it included many of the points found in other articles links here.
- Snooze, You Win
Chris Carmicheal is quoted in the article, stating that naps
were critical in [Lance Armstrong's] overall training plan. The article goes on to provide tips on how to get the perfect nap.
- Sleep: Use It or Lose It
A look at sleep and how it may effect a high volume athlete. A great quite on here from Gordy Byrn:
your recovery strategy is the most important part of your plan. Recovery [a.k.a. sleep] is when you make all your fitness gains.
- Mechanisms Of Melatonin & Sleep In Athletes
A discussion about the effects of sleep and melatonin on the body. Well worth reading.
- Sleep And Performance: Just how crucial is a good night's sleep before a major event?
Another article that presents the stages of sleep, this one commenting on the release of growth hormone during slow wave sleep. It also presents mixed findings about performance degradation (mentally and physically) due to sleep deprivation.
- Lack of sleep can reduce an athlete's cardiovascular performance by 11%
If an athlete needs eight hours’ sleep yet only gets six, he/she will accumulate enough sleep debt in 15 days to significantly reduce their cardiovascular performance.
This report is an eye opener; not only does it provide a good write-up of the different sleep stages, but it specifically talks about the stages and how they pertain to athletes with respect to cardiovascular fitness, mental performance and emotional stability. It also offers 8 questions to determine the amount of sleep you need:
- Do you frequently fall asleep if given a sleep opportunity (a sleep opportunity is defined as a quiet, dark environment for at least 10 minutes)?
- Do you usually need an alarm clock to wake you?
- Do you tend to catch up on sleep during the weekends?
- Once awake, do you feel tired most mornings?
- Do you frequently take naps during the day?
- When you can get it, do you consistently sleep more than 9.5 hours per night?
- Do you feel lethargic or slow throughout the day?
- Do you sleep longer during times of depression, anxiety and stress?
- A guide to the perfect power nap
This article offers a description of the five stages of sleep, which run approximately 90 minutes in total, and recommends 20 minutes for a powernap while adding that 50 minutes will keep you from experiencing sleep inertia.
- How to Sleep Like an Olympic Athlete
This article contained the same advice as many others, but had a couple of extra bits of info:
"The room temp needs to be on the cooler side," says Daniel McNally, MD, director of the Sleep Disorders Center at the University of Connecticut Health Center. "Your body temperature tracks your circadian rhythm, so as night begins, your body temp falls and it reaches a minimum right after you go to bed. If you are in an environment where you can't lose body heat, for instance if it's hot and humid, you won't sleep well."
"Sleeping in low light is important," says Mednick. "You need the hormone melatonin to sleep, and melatonin is only released under low-light conditions."
- MetroNaps Science
While perhaps not an unbiased source for info, it provides some advice and facts about napping.
- Lack of Sleep Affects Hormone Levels
This is a short article that contained the following bit:
Independently of age, the amount of GH secretion was significantly associated with slow wave sleep.
- How to Take A Caffeine Nap
You drink a cup of coffee and immediately take a 15 minute nap. Researchers found coffee helps clear your system of adenosine, a chemical which makes you sleepy. So in testing, the combination of a cup of coffee with an immediate nap chaser provided the most alertness for the longest period of time.
- Ask Metafilter
Some tips in here and, in general, you can see that everybody has to find their own little method for getting naps right.
- The restorative effect of naps on perceptual deterioration (pdf)
This article has been quoted in a few sources and news stories that I came across.
- Miles to Go Before I Sleep
An article featuring Dr. Claudio Stampi,
whom sailors often refer to as Dr. Sleep, is the go-to guru when you want to race sailboats alone across the ocean on ridiculously small amounts of shut-eye.It covers his work on polyphasic sleep, and has some interesting quotes:
His research also showed that afternoon siestas were chock-full of slow-wave sleep, the type that appears to be most important for recharging the body.
- Catching Catnaps
A transcript of a PBS program featuring an experiment done by Dr. Claudio Stampi as he tests a person using the polyphasic sleep method.
- New Parenthood and Sleep Deprivation
The title says it all; the section on The benefits of napping offers some numbers and shows that napping is a must for new parents.
- The power of the Sleep Cycle
An interesting article about one person and their experience with hacking sleep.