How to Use Light Therapy to Change Your Internal Clock and Sleep Better

Use carefully timed light therapy to optimize your sleep

Do you feel very sleepy at 9 pm but want to stay up until 11?

Are you in bed at 11, yet can’t fall asleep for another hour?

Perhaps you have traveled across several times zones and now, even several days later, you feel sluggish and jet lagged.

All of the above are signs that your habits and desires and your biological clock are out of sync. And for most people the clock can’t be forced into sleep mode like an on-off switch.

Carefully timed light therapy, that is, exposure to blue, blue-green, or blue-enriched white light either in the evening or in the morning can be a fast and elegant way to set your clock to align with your lifestyle, sleep better, and even overcome serious insomnia.

My motivation for exploring light therapy for sleep

I often alternate between living in a small town for a few weeks and staying in a large bustling city. In the country side, folks are usually in bed by 9 pm; there is little else to do in the evening.

Quite quickly, I settle into a routing of having dinner, then watching TV for an hour or so – basically until I feel sleepy, which is usually pretty soon. So by 9 or 10 I am in bed and dozing off. I believe I have always been more of a lark, a morning person who tends to go to bed early and rises early. In fact, as I get older I become even more of an early riser.

This doesn’t suit me well when I am in the city though.

If I were to go to bed too early, noise would likely prevent me from falling asleep, and from hanging out with friends and drinking a few beers at night. Naturally my beer consumption also goes up when I am around town.

While in town, I would much rather go to bed at around 11:30 pm and maybe wake up at 7 or even 8. Being among other people and exposed to lots of light, I usually manage to stay up until 12 am and then go home and fall asleep quickly.

Unfortunately, I wake up at 4:30 or 5 am.

This would be fine when going to bed and 9 or 10, but with my later bed time I only get about 5 hours of sleep: a perfect recipe for feeling low on energy and sleep deprived.

It takes me quite a few days or even weeks to nudge myself into waking up later.

For many years, researchers at the sleep lab of Flinders University in Adelaide, South Australia have been researching the use of bright light therapy and blue-green light to help people optimize their sleep and overcome insomnia.

They were initially focusing on people with delayed sleep phase disorder (DSPD), also known as delayed sleep phase syndrome and advanced sleep phase disorder (ASPD), aka advanced sleep phase syndrome.

Now they are also applying their research to help frequent travelers overcome jet lag and shift workers adjust to a markedly different sleep-wake schedule.

In a way, you could even consider party people as shift workers.

Owls and larks and everyone in between

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How to Block Blue Light for Better Sleep and Why It Works

Special blue-blocking glasses, lamps that emit no blue and little green light, and apps that shift the color temperature of our smartphones and iPads have been designed to remove potentially sleep-disrupting light.

But how do these blue blocking glasses and lamps help with sleep?

And how do they need to be designed and used to actually work?

How to block blue light for better sleep

A couple of years ago, I was often riding the subway home late in the evening, coming either from work or a night on the town. For the first couple of minutes, I usually felt very sleepy and was ready to go to bed. At the end of my ride though, I was completely alert. At some point, I started wondering whether the bright light in the subway car might be responsible for my alertness at the end of the ride.

I had previously heard of morning bright light therapy to wake people up and treat bad winter moods, and the subway car seemed to be doing just that.
The problem: we were in the middle of the night!

Looking further into the alerting effects, I came across a whole line of research that had identified the blue light portion of white light as the most potent wake-up signal.

In 2001, researchers identified novel photosensitive cells at the back of our eyes, and these cells were most responsive to blue light. What’s more, they are directly connected to our biological clock. It has been found that light exposure to these cells resets our internal clock, suppresses melatonin, and keeps the clock in sync with our 24-hour day.

Likely unaware of these findings, from 2005 on governments were starting to pressure manufacturers and households to get rid of incandescent light bulbs and replace them with more energy-efficient compact fluorescent lamps and later white LEDs.

As it turns out, most of these lamps contain a lot more blue light than the old bulbs, and they have also been found to be a lot more effective at suppressing melatonin, the primary hormone that signals darkness to the cells in our body. The same goes for modern LED-powered devices including smartphones, tablets, and PCs.

Let’s look at how light impacts our biological clock

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Choosing and Using the Ideal White Noise Machine for Sleep

In this post, we will look at the most suitable white noise machine for sleeping, and how to use it for maximum effect and fewest side effects. I have also summarized research findings regarding white noise and sleep.

The ideal white noise machine for sleeping

Many years ago, I stumbled across my first sleep-aid sound conditioner by chance. At that time, my bedroom window was facing a small, but pretty noisy street. During winter, I used a small ceramic heater that had a fan to distribute the warm air. As it got warmer in spring, I was ready to put the heater back in storage.

I noticed, however, that it was a lot easier to fall asleep with the little heater running, so I even put up with a slightly overheated room just to get my fan noise.

Later I used a normal room fan. It wasn’t loud enough for me though.

A friend had the solution: I punched a few holes in a plastic bag and covered the fan with the bag. Voila – I had a loud white noise machine.

I am aware that this isn’t a safe way of doing things: So don’t try this at home. Don’t cover your fan with a plastic bag.

At that time I didn’t know, but there are a lot better solutions readily available… Continue reading

My Top 6 Noise Blocking Earmuffs Review

In this post, I want to provide an overview and detailed review of noise blocking earmuffs.

Regular readers of my Blog know that I am into blocking noise to reduce stress and improve cognitive performance and sleep. Many studies show a large positive impact of noise reduction on all kinds of mental tasks, including studying, reading comprehension, writing, serial memory, proof reading, mental math, and so on.

my top 6 noise blocking earmuffs review

As a student and as a professional, you can improve your performance on almost any task by controlling the noise you are exposed to while working. In addition, by removing disturbing noise from your environment, you can reduce stress levels, improve general well-being, and prevent permanent hearing impairment.

Earmuffs are also becoming increasingly popular with people who are hypersensitive to noise, and sufferers from hyperacusis, misophonia, autism and ADHD.

I have found noise cancelling earmuffs to be among the most effective tools for studying. And it’s not only me: Search Google Images for memory championships and you will see participants wearing industrial earmuffs.

This review looks at general noise blocking effectiveness of different earmuffs and comfort and suitability for different types of noises, including low frequency noise and human speech. I focus on enhancing cognitive performance and general well-being rather than hearing protection in industrial settings and on the shooting range. That being said, you will find an in-depth comparison of manufacturers’ attenuation data.

In my quest to find the most effective, most comfortable and most fashionable earmuffs, I have purchased and used quite a number of different models. In this review I am going to look at the following:

  • Overall noise blocking effectiveness
  • Low-frequency and human speech blocking effectiveness
  • Comfort
  • Manufacturing quality and durability
  • Discreteness
  • Earmuffs for sleeping

The models in this review include:

  • 3M Peltor X5A
  • 3M Peltor X4A
  • 3M Peltor Optime 105
  • 3M Peltor Optime 98
  • 3M Peltor Optime 95
  • Howard Leight Leightning L3 (with some references to the Leighting L2 and Leightning L1)

My personal earmuffs ranking

Before I delve into the details about which earmuffs are best for which application, here is my overall ranking. Please note that this ranking is personal and does not only account for noise reduction, but also general usability, comfort, weight, build quality, and price. Continue reading

Happy, Relaxing Floating – First Experiences with Float Therapy

Recently, during an extended stay in Taiwan, I started with floating sessions.
Flotation tank with open lid.

Every other week, I float for about 70 minutes in a tub filled with magnesium-sulfate-saturated water, a so-called flotation tank, also known as an isolation tank.

The water is kept at skin temperature, and the tank is supposed to be sound and light proof. Upon closing the door or lid, it is pitch dark, and you hear almost nothing.  Float therapy was originally devised to answer the question “what happens to the brain in the absence of sensory stimulation?”

In the meantime, it has become a popular tool to reduce stress, solve creative problems, help with insomnia, and improve performance, among others.

So far, I have done two sessions, with more coming up.

I have found that floating can be very relaxing and uplifting. With this post, I would like to inspire you to try it yourself.

How to prepare for floating?

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How to Block out Snoring Noise

In my previous post, I explored how day-time noise impairs our cognitive performance and what we can do about it. But there is another big elephant in the room – our night-time sleep. Sleep or the lack of it has a big impact on our ability to perform at our best, both physically and mentally.

Less or disrupted slow-wave sleep, for example, entails poor memory and poor wound healing.

Among the worst offenders interrupting our night-time sleep is the all too familiar sound of SNORING. Snoring can be loud – very loud indeed. A loud snorer can reach more than 90 decibels of peak sound pressure level. That is about as loud as a lawn mower.

How to block out snoring noise

Intrigued by the capabilities of some of the newer devices to block out noise and sophisticated white noise apps, I decided to run an experiment to answer this question: What is the best way to block out snoring noise?

Test equipment and candidates

  • An iPad equipped with a sound level meter (Noisee for iOS).
  • Two different white noise apps: myNoise for iOS and White Noise by Tmsoft for iOS and Android.
  • Earplugs of different sizes by Hearos, 3M, and Mack with a noise reduction rating (NRR) of 29-33 (an NRR of 33 is about as good as you can get).
  • Good-quality earbuds (a good fit is vital for sound quality and noise isolation).
  • The best earmuffs I could find, with a noise reduction rating of 31 (3M Peltor X5A).
  • DIY noise isolating earbuds and sleep headphones.
  • The best noise cancelling headphones I could find (Bose Quiet Comfort QC35).

Testing the snore blocking effectiveness

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How to Take the Perfect Nap for Performance, Mood and Memory

how to take the perfect nap

I have been an afternoon napper for more than 14 years. I started napping after moving to a country where most people took a siesta. For various reasons, I just couldn’t get enough sleep during the night, so it was easy to fall asleep.

Over the years, I have tried short power naps, 60-minute naps, and occasionally 90-minute mid-afternoon sleeps. In this post, I would like to share with you how to nap for better mood, alertness, concentration, improved memory, and restoration of learning capacity. We will cover how long and when to nap for maximum benefit, how to avoid after-nap grogginess (sleep inertia), and the possible risks associated with longer naps.

As a final point, I am going to share my personal napping experience and my favorite napping hacks.

The benefits of napping are numerous

For me personally, the most important benefits are improved mood and decreased sleepiness. I just feel happier and ready to tackle my afternoon after a nap.

Napping studies have found a large number and variety of benefits of napping in all kinds of workplace and operational settings.  Studies looked at drivers, commercial airliner pilots, shift workers, doctors and nurses, students, children, senior citizens…

Here is a non-exhaustive list of research-proven benefits:

  • Improved cognitive performance
    • Increased alertness and concentration
    • Decreased reaction time
    • Speed and accuracy improvement on cognitive tasks
  • Better mood
  • Less sleepiness and fatigue
  • Significantly reduced number of driving incidents such as drifting out of one’s lane in a car simulator experiment: the number of incidents caused by drivers who had taken a 15-minute coffee nap (see below for details) was 91% less than for drivers who had just taken a break. Coffee alone reduced the number of incidents by 66%.
  • In a NASA study, pilots who took naps were able to maintain their performance and reduce incidents during a demanding multi-day schedule. Pilots who weren’t allowed to nap experienced deceasing performance and a significantly larger number of incidents, including during the descent and landing.
  • Significantly Improved memory and protection of learned information from interference: a study that focused on declarative learning found a 60% increased memory retention for nappers at a final test one week after initial learning, compared to learners who hadn’t napped.
  • Nappers perform better at abstracting general concepts and making connections that weren’t directly learned but can be inferred from what was learned (relational memory).
  • A nap can restore the capacity to learn, which otherwise deteriorates considerably with time awake.
  • Performance on a creative problem solving task where subjects had to find a linking word between three seemingly unrelated words was improved by more than 40% after a 90-minute nap containing REM sleep (see below) compared to rest and naps containing only non-REM sleep.

To better understand what nap length you should aim for, here is a sleep architecture primer

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