Science in Action: Why Did I Sleep So Well? (part 9)

From Nassim Taleb’s web notebook:

I was going to have dinner with Seth Roberts in San Francisco. So, out of curiosity, I tried his diet [ clipping my nose and consuming two large tablespoons of flaxseed oil ] . . . When someone who observed me with a noseclip asked: “what are you doing?” , I gave my answer “trying to be healthier”.  It elicited a smile: “Why don’t you dance outside on one leg for ten minutes? That too may work very well”.

Strange strange coincidence.

Why Did I Sleep So Well? directory.

Science in Action: Why Did I Sleep So Well? (part 8)

My recent experience suggests that if I stand on one foot until it becomes slightly difficult about four times/day I will sleep much better. Two days ago I measured how long those four bouts of one-foot standing actually were: 6.2 (left foot), 4.3 (right), 4.8 (left), and 5.2 (right) minutes. The median is 5.0 minutes. When I started doing this, about two weeks ago, each bout was about 2 minutes.

It doesn’t seem to matter when I do them. Now I do two in the morning and two in the evening. Fits perfectly with a subway commute. You’ll want to be forced to stand.

In the evening I have a pleasant sense of anticipation: I will fall asleep and wake up feeling really good. I have never before felt this way. I have slept this well before, when I stood 9 or 10 hours/day. The sheer difficulty and all-consumingness of doing that, I now realize, got in the way of anticipating the benefits.

Something else curious is that one-foot standing leaves no mark — I can’t tell at 3 pm how many bouts I’ve done so far just by noticing how I feel. Unlike water or calorie consumption: If I don’t drink anything I’ll get thirsty. If I don’t eat anything I’ll get hungry. But if I don’t get enough of this particular byproduct of exercise I’ll never notice.

Science in Action: Why Did I Sleep So Well? (part 7)

I’ve continued to sleep extremely well. I’m sure there’s something to this. I’m almost sure it’s because of the one-legged standing.

Here are some technical details. I usually do four bouts of one-legged standing, two in the morning and two later. During each bout I stand on one leg, pulling my other leg up behind me. Sometimes I touch something to balance myself. Usually I watch or read something at the same time. Each bout lasts until it’s hard to continue — until it becomes slightly painful. At first the bouts lasted about two minutes, now they last about four minutes. I enjoy it more when I time it with a stopwatch.

I haven’t yet systematically varied the number of bouts but I suspect one is too few to get the full effect and four is plenty. I’m still trying different ways of arranging them throughout the day. Doing all four at once is too tiring — it takes too long to recover. Maybe it’s best to do two whenever’s convenient during the day and then do two more in the evening when it’s okay to be tired.

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Why Did I Sleep So Well? directory

  1. Initial observation, 9 possible causes
  2. Another possible cause: standing on one foot
  3. Sleep almost great, narrowing possible causes to two.
  4. Sleep great again, narrowing possible causes to two
  5. Sleep great again after only standing on one foot
  6. Someone else gets similar results
  7. Technical details
  8. How long I stand
  9. Eerie coincidence
  10. Patterns of discovery
  11. Comparison to other sorts of exercise
  12. What’s a good dose?
  13. How much I’ve been standing Comparison with conventional exercise.
  14. Two more people get similar results
  15. How long I stand (continued)
  16. Replication details
  17. The amount of time needed stops increasing

Science in Action: Why Did I Sleep So Well? (part 5)

I have been sleeping much better than usual. Sharp easy-to-notice improvement. After the first time this happened I made a list of 9 possible reasons (lifestyle changes that might have been responsible). I later added one I’d overlooked: standing on one foot to exhaustion a few times.

Yesterday I stood on one foot to exhaustion four times, twice in the morning and twice in the evening. It took about three minutes each time (12 minutes total). Didn’t make any of the nine other candidate changes. And I slept much better than usual. So it is beginning to look like just that one factor is responsible. The one I almost forgot but also the one that seemed most plausible after i remembered it.

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Science in Action: Why Did I Sleep So Well? (part 4)

I repeated the two things that remained on my list as possibilities for why I slept so well a few nights ago: 1. Looked at my face in a mirror a half-hour earlier than usual with a better sound source. 2. Stood on one foot until exhaustion (6 times). Lo and behold, I slept great. Now I’m pretty sure one of these two, or their combination, is responsible.

An unexpected twist is that I only slept 5 hours. Usually I’d still feel tired after that little sleep. But I feel like I slept 7 or 8.

I suspect the standing, not the faces, is the cause. Which would be ironic. Of the treatments I’ve studied by self-experimentation and found helpful, standing 9 or 10 hours, which greatly improved my sleep, was the most difficult. I loved what it did to my sleep. I still remember how wonderful it felt to be so well-rested the next morning. Even so I stopped doing it. As an experimental treatment, it was hard to measure how long I stood. As a lifestyle change, it was really hard to arrange so much standing. Whereas standing on one foot to exhaustion six times might be the easiest effective treatment I’ve studied (if it’s effective). Easy to measure, nothing to buy, no logistical problems.

I may try to repeat the earlier observation a few more times — as a kind of gift to myself — but now the main thing I want to do is separate the effects of the two factors, i.e., test one without the other.

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Science in Action: Why Did I Sleep So Well? (part 3)

Yesterday I did two of the 10 or so possible things that might have caused me to sleep really well recently: (a) looked at my face in a mirror earlier than usual with voices behind the mirror (Factor A) and (b) stood on one foot until exhaustion (twice) (Factor B). And last night I slept better than usual — not quite as great as the first time but still really well. This seems to narrow down the possibilities to:

  • Factor A only
  • Factor B only
  • Factor A and Factor B

I have doubts about Factor A. After I figured out that seeing faces in the morning improved my mood, I tried for months to find the right “dose” (right time, right length) to improve my sleep. I didn’t find it. Whereas Factor B is merely a new version of something that has improved my sleep countless times, so much that I’ve noticed its effects when not looking for them. The effect might have been less clear last night than the first time because I only stood on one foot to exhaustion twice. The first time — I wasn’t paying attention, of course — I think I did it three or four times.

So today I did it six times. It was curiously exhausting. After I felt recovered (about an hour later), the rest of the day I felt really good, cheerful and energetic — better than after yoga. That doesn’t make a lot of sense. If I do something that makes me sleep better, shouldn’t it make me more tired?

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Science in Action: Why Did I Sleep So Well? (part 2)

A few days ago (Tuesday night) I slept unusually well, presumably because Tuesday day had been unusual in some way. I made a list of nine possible reasons.

Today I realized I’d forgotten something: 10. Stood on one foot more than usual. To pass the time while looking at my face in the mirror I had stood on one foot while stretching the other leg, pulling my foot up behind me. I was curious how long I could do this so I did a few trials with each leg where I did it until it became too painful. I lasted about 2 minutes on one leg and 2.5 minutes on the other.

This might seem trivial — and I forgot about it. But standing on one foot continuously for a relatively long time surely stressed my leg muscles much more than usual. Previous research convinced me that standing many hours improves sleep. Maybe this “extreme standing” produces the same hormonal effects in a few minutes as normal standing does in ten hours. That would be wonderful!

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How Should We Fight Infections?

In the latest New Yorker, an article by Jerome Groopman is about the emergence of even-more-antibiotic-resistant bacteria.

I asked him what we should do to combat these new superbugs. “Nobody has the answer right now,” he said. “The fact of the matter is that we have found all the easy targets” for drug development. He went on, “So the only other thing we can do is continue to work on antibiotic stewardship.”

All the easy targets, huh? Here’s an easy target that hasn’t been exploited: Why are colds more common in the winter? Many diseases are more common in the winter. I believe it’s because sleep is worse in the winter. While you are asleep is when your body does its best job of fighting off infection. When I vastly improved my sleep — by standing much more, and by getting more morning light — I vastly reduced the number of easy-to-notice colds that I got. I still got cold infections, I think, but they merely caused me to sleep more than usual for a few days.

Several years ago I noticed an introductory epidemiology course in the UC Berkeley School of Public Health was taught by someone I knew. I called him. “Is your course going to cover what makes our ability to fight off infection go up or down?” I asked. No, he said. That is the usual answer. The question of why colds are more common in the winter is not part of the traditional study of epidemiology.

The connections between sleep and fighting off infection are so strong I’m pretty sure I’m right about this (that colds are more common in the winter because sleep is worse). Why, then, haven’t sleep researchers looked into this? Strangely enough, they may not have thought of it; I haven’t come across this idea in any book about sleep I’ve read. (If you’ve seen it somewhere, please let me know!) Justifications of sleep research tend to revolve around car accidents, which are often caused by too little sleep.

More. My point is not that poorer sleep causes more colds in the winter; it’s that it’s an easy target. Suppose you think the colds/winter connection is caused by less Vitamin D in the winter. An experiment in which one group gets Vitamin D supplements in the winter and another group doesn’t is easy to do, given the great health implications.

Morning Light and Better Sleep

Song Cato, a friend of mine in Taiwan, writes:

I was very surprised that the quality of my sleep greatly improved after I switched to waking up at 5:30 am and walking in the park soon after that. I started it about a month ago. The park is packed with people doing everything from tai chi to ballroom dancing. I used to go to bed at 1 or 2 am. and wake up between 7 and 8:30 am with a foggy head. Now sometimes I feel tired and go to sleep at 10 pm which has never happened in my life since I went to middle school.

She got the idea from me. I go outside around 7 am every morning and fall asleep between 11 pm and midnight.

More. She gets up at about 5:15 am and gets outside about 5:30. She stays outside for at least 2.5 hours, mostly in the park, where she walks, talks to vendors, shops a little, and does simple stretching exercises. Talking to vendors = very good!

Less Carbs –> Better Sleep?

I haven’t heard this before:

My insomnia seems to have gone. This may be something to do with my bold adherence to Nassim Nicholas Taleb’s low carb diet. I have not drunk and barely eaten a single gram of carbs for the last two and a half weeks. I am ten pounds lighter and I sleep like a baby. . . . I am attaining a steady seven and a half hours of unconsciousness nightly. This hasn’t happened in at least ten years, possibly more. I have also become optimistic, amiable and energetic.

Perhaps drinking less alcohol improved his sleep. This has nostalgic interest for me. A turning point in my self-experimentation came when I analyzed my data and saw that I started sleeping less exactly when I lost weight (by eating less processed food). In a complicated way this helped me discover that eating breakfast caused me to wake up too early.

Thanks to Dave Lull.

Science in Action: Sunlight and Sleep (more progress)

Surely we need sunlight to sleep properly. But how much? Rats can be synchronized to a 24-hour activity rhythm with a relatively small amount of light (such as one hour) every 24 hours. This is one reason for the emphasis on morning light by sleep doctors mentioned in a previous post.

I have agreed with them. For the last 10 years I have gotten one hour of sunlight-like light every morning from a bank of fluorescent lights on the handles of my treadmill. The lights shined up at me while I exercised and watched TV. This, I thought, allowed me to get a good dose of light with low variance in when and how much and to combine light-getting with exercise. I never questioned this routine.

Then came the event that led to this Sunlight and Sleep series: In the airport during a trip to New Orleans, a student told me when she sunbathes, she sleeps better. When I got home from my trip I tested her idea. Me, too: When I was outdoors a lot (in the shade), I slept better.

I took another trip (to Los Angeles). When I got back from that trip, I decided that I would adjust the timing of the treadmill light so that it interfered less with my day. I shifted it from 9:00 am to 10:00 am (original timing) to 8:00 am to 9:00 am (new timing).

To my surprise I started waking up too early, so often it could not be a coincidence. The only change I had made was timing of the light. So the treadmill light was making things worse! I stopped it entirely. My sleep improved — no more early awakening. Huh.

Here are details:

Period 1 (treadmill light 9-10 am, little sunlight): woke up early 29 days out of 99 (29%)

Period 2 (treadmill light 9-10 am, lots of sunlight): woke up early 1 day out of 25 (4%)

Period 3 (treadmill light 8-9 am, lots of sunlight): woke up early 4 days out 8 (50%)

Period 4 (no treadmill light, lots of sunlight): woke up early 0 days out of 8 (0%).

Lots of sunlight means 6-8 hours exposure to light of roughly 1000-2000 lux. Sitting in the shade or inside next to a big window is always enough. At the low end (1000 lux) my laptop screen is easy to read; at the high end (2000 lux), which I try to avoid, it becomes slightly hard to read.

Science in Action: Sunlight and Sleep (more background)

An early section of Wide Awake (2006), Alan Berliner’s documentary about his life-long insomnia — he can’t fall asleep until 3 or 4 am — lists common folk remedies:

BERLINER Over the years I’ve tried to cry myself to sleep, to drink myself to sleep, aroma therapy, changing mattresses, changing pillows, lavender beads, massage therapy, white noise, meditation, counting sheep, melatonin, Valerian root, acupuncture, acupressure, chamomile tea, warm milk, hypnosis even, yoga, homeopathic medicines, marijuana, lots of sex, hot baths, herbal teas, biofeedback.
SISTER Okay, nothing worked.

Conspicuously absent: sunlight. At the end of the movie, however:

DOCTOR We have to reset your [internal] clock. Since you’re such a night owl, I’d like to move your sleep cycle earlier by having you get light exposure in the morning. When you wake up, throw on some clothes and go outdoors for an hour. I really want light to get into your eyes ’cause that’s what going to move your rhythm so you can fall asleep earlier.
ANOTHER DOCTOR Light is one of the most powerful cues for your internal clock to know what time it is. You see light and it tells you: be active during the day, sleep at night.

But the treatment they settle on is sleep deprivation: “I’d like you to spend just 6.5 hours in bed,” says a doctor. “Give you less time in bed than you want. . . . 2:30 to 9:00 am would be a reasonable way to go.” “You are going to be dysfunctional,” Berliner is warned. The film ends: “Now that I know what I have to do, the question is: Can I do it?”

This is a good summary of what people believe about how to cure insomnia. Sunshine is absent from the folk remedies you are likely hear. When doctors mention it, they emphasize early-morning sunlight.

Until recently, I too thought that sunlight exposure was important in the morning, but not during the rest of the day. Every morning I exercised on a treadmill with sunlight-spectrum light shining on me for an hour; I thought that was enough. Now I am adding to that sunlight later in the day — in the afternoon, for instance — and finding that it helps.

Science in Action: Sunlight and Sleep (progress report)

I’ve collected even more observations supporting the idea that outdoor light improves my sleep, as discussed earlier. Now I’d like to get some idea of the dose-response function. To sleep really well do I need two hours of outside light? Four hours? Eight hours?

I’ve started to rate my sleep on a scale where 50 = average sleep (average for the months before I started spending more time outside) and 100 = best sleep imaginable (which I got after standing about 10 hours). And I’ve started to use a stopwatch to measure how long I spend outdoors. I’ve also been using a light meter to measure the strength of light in various places. When I’m outdoors it’s almost always in the shade. Today I discovered that sitting indoors next to a cafe window the incident light was just as bright as when I sit outside. Great to know because indoors I can plug in my laptop.

A 1994 book chapter from Daniel Kripke‘s lab reported a correlation (0.24) between low light exposure and “abnormal sleep.” So the connection I am now studying has been plausible for many years. The measurements I am now making are easy, but no one made them. Perhaps too many people believe that anything other than a double-blind trial with control and experimental groups is, as Peter Norvig, Google’s Director of Research, believes, a “mistake.”

Science in Action: Sunlight and Sleep (update)

Today I had lunch with a friend and said, “I’d like to sit outside.” I answered my phone indoors and went outside. I answered my email sitting outside.

I’m now convinced that more outdoor light exposure makes me sleep better — better in the sense that I wake up feeling like I have slept more deeply. Whatever sleep does, it has done more of it. I’m convinced because I have gotten this well-slept feeling after six or seven days during which I spent several hours more than usual outdoor and did not get this feeling after two days when I spent an average or less-than-average amount of time outdoors.

I have slept this well before, but only after standing for 9 or 10 hours, which wasn’t easy. (Nowadays I stand about 6 hours/day.) Whereas spending more time outside is easy. I’ve ordered a sunshade for my laptop.

I am going to start to measure my sleep quality with a rating and keep track of how long I spend outdoors.

Science in Action: Sunlight and Sleep (background)

Daniel Kripke, a professor of psychiatry at UC San Diego, has done lots of research on the effect of exposure to varying amounts of natural light. His subjects often wear meters that record the illumination level. His latest paper (2004) on the connection between outside light and sleep reports several weak correlations between amount of light exposure and sleep quality:

mesor log10[lux] [a measure of light exposure] was . . . positively correlated with sleep quality (rp = 0.17, p < 0.005), and negatively correlated with reported trouble falling asleep (rp= -0.17, p < 0.005), waking up several times a night (rp= -0.18, p < 0.001), waking up earlier than planned (rp= -0.09, p < 0.10), and trouble getting back to sleep (rp = -0.11, p < 0.025).

The introduction states:

Bright light has been recommended for treatment of various sleep disorders [13], but very few experimental trials have been reported.

“Very few” seems to mean none, given the absence of citations.

The paper ends:

In conclusion, low illumination has a small relationship to . . . sleep disturbances.

Science in Action: Sunlight and Sleep (could it be? continued)

Yesterday I deliberately spent almost all day indoors. I didn’t change anything else. This morning I woke up feeling less refreshed than usual. Here are the last three days:

Day 1: Try to spend lots of time outdoors (in the shade). Result: Wake up feeling more refreshed than usual.

Day 2: Try to spend lots of time outdoors (in the shade). Result: Wake up feeling more refreshed than usual.

Day 3: Try to spend as little time outdoors as possible. Result: Wake up feeling less refreshed than usual.

My belief is increasing. Via Google I found this:

Person 1: During the warm months of the year, I swim …a lot! . . . The amount I sleep during swimming season can increase by 1-2 hours.

Person 2: Your probably sleeping longer due to all the extra calories and physical exerction you use by swimming.

Person 1: Nah, it’s the same physical exertion year round for me. I exercise year round. But in the warm months, my exercise takes me outside where I am exposed to sunlight instead of artificial indoor light. That’s how I know it’s the sunlight that helps me sleep better.

I also found this:

We have found that people who are outdoors more have fewer sleep problems.

From an interesting mini-book about the dangers of sleeping pills (apparently the new ones cause cancer). I haven’t yet found the study it refers to.

Science in Action: Sunlight and Sleep (could it be?)

In an airport a few weeks ago, chatting with a stranger, I told her about my self-experimentation. When I stand a lot, I sleep better, I said. She said that sunlight had the same effect on her: When she sunbathes, she sleeps better. Better how? I asked. More deeply, she said.

I had found that morning sunlight (an hour, say) helps me sleep. Her idea was different: No one sunbathes in the morning. She was saying that the amount of sunlight matters independent of the time of day.

This was fascinating because I remembered two days, prior to studying the effects of standing and morning light, after which I had slept very well (i.e., woken up feeling very well-rested):

1. A day when I went to many artists’ studios to look at their work (an event called Open Studios).

2. A camping trip.

Both days I was on my feet a lot. But both days I was also outside a lot, I realized.

Yesterday I gave her idea a test: I spent more time than usual outside — about three hours more, I’d guess. I spend a lot of time sitting in cafes writing; yesterday I sat outside instead of inside.

This morning I woke up feeling unusually well-rested. This bears more investigation.