The October 2015 Scientific American has a fascinating article on sleep: Beyond Memory: The Benefits of Sleep.
- Sleep is an unconditional necessity.
- College students given an immunization that had normal sleep had a 97% higher antibody response than subjects kept awake all night the following night (one night only!). In another study, antibody protection increased 56% for each additional hour of sleep! With less than six hours of sleep, vaccinations were ineffective (no clinically significant immune response) (Hepatitis B).
- When sleep deprived, negative memories are formed more strongly than positive ones, and cognitive decline occurs more strongly with positive associations; negative associations are least affected.
- Poor sleep can lead to major depression and may contribute to other psychiatric disorders; the use of CPAP (to address sleep apnea) shows a 26% reduction in depression symptoms in one study.
- Five nights of restricted sleep with a dozen men showed that the appetite-stimulating hormone ghrelin increased by 28%. Amounts of leptin (decreases hunger) decline by 18%. The men reported a 23% increase in hunger. In other words, sleep deprivation can lead to weight gain (an idea supported by 50 other studies).
- Children from 6 to 9 years old getting less than 10 hours of sleep were 1.5X to 2.5X likely to be obese. Studies in adults suggest a 50% increase in obesity with less than 6 hours of sleep (average) and an associate with Type II diabetes is also seen.
I’ve long held the theory that the more consistently I excercise (60-90 minutes per day), the better I feel and the better everything works. I based this idea on a simple theory: increased blood flow to the body helps all sorts of systems flush toxins, repair and oxygenate tissues, deliver nutrients, etc. Along with the benefits of excercise in general.
Might my theory have a solid basis in scientific fact? If blood flow exerts the powerful effects now being discussed, then the hugely increased blood flow while vigorously excercising surely exerts side affects from pumping large amounds of blood over thousands of hours over the course of a year.
Blood exerts a powerful influence on the brain
The brain's nerve cells have a call-and-response relationship with the blood that sustains them
Blood tells a story about the body it inhabits. As it pumps through vessels, delivering nutrients and oxygen, the ruby red liquid picks up information. Hormones carried by blood can hint at how hungry a person is, or how scared, or how sleepy. Other messages in the blood can warn of heart disease or announce a pregnancy. Immune molecules can reveal an infection. When it comes to the brain, blood also seems to be more than a traveling storyteller. In some cases, the blood may be writing the script.
This line of research is expanding scientists’ view of what makes the brain tick, and the implications for human health are enormous. Diabetes, multiple sclerosis and hypertension— diseases that harm blood vessels elsewhere in the body — may afflict the brain too. What’s more, common drugs that tinker with blood flow, including statins, anti-inflammatories and even Viagra, may affect how the brain operates.
... Vast networks of endothelial cells may carry messages lightning-quick from neurons that need fuel to distant large arteries that can supply it
.. Beyond keeping neurons well fed, blood may actually tell neurons when to fire. Kind of like gasoline oozing out of a car’s gas tank and taking the wheel.
... A slight dilation or constriction of vessels reliably changes the behavior of nearby neurons.
... Abnormal blood flow in the brain is present in the five major forms of dementia, including Alzheimer’s disease and dementia with Lewy bodies
... Other disorders, such as diabetes, might harm the brain by damaging blood vessels. Many scientists attribute the mental fuzziness that can accompany diabetes to neuron damage from excess glucose. But maybe faulty lines between unresponsive blood vessels and neurons are to blame...
... Common drugs that influence blood flow may also have unanticipated effects on the brain. In addition to statins, drugs such as Viagra, blood pressure drugs and even anti-inflammatories may unintentionally change how the brain operates. These drugs may be dampening the brain’s ability to call for blood when it needs it...
I wrote about my nasty experience with nerve damage from Flagyl (Metronidazole), and how when I asked “any risks”, my doctor lied to me with a resounding “NO”.
Fortunately, I have mostly recovered over a period of 11 months (usual prognosis for recovery is 12-18 months so that’s good), but I still suffer pain in my left arm regularly, as well as some lingering effects in my toes.
But now it turns out that my “head in the sand” theory about medical doctor ignorance has solid basis in fact—devastating side effects are in fact possible with a wide variety of antibiotics, and this has long been a blind spot with the medical profession, conveniently not reported and thus ignored.
The issues are not just with Flagyl, but with another entire class of antibiotics causing nerve damage, tendon damage, cardiovascular damage, etc. I would say this: use an antibiotic only when absolutely necessary.
FDA Panel Seeks Tougher Antibiotic Labels
Mounting evidence of previously unknown, and sometimes permanent, side effects prompted review
Food and Drug Administration advisory panel overwhelmingly called for heightened label warnings on widely prescribed antibiotics called fluoroquinolones because of unusual but sometimes devastating side effects.
Most fluoroquinolones now are sold as generic drugs, but the well-known brand names include Bayer AG’s Cipro, generically called ciprofloxacin; and Johnson & Johnson’s Levaquin, or levofloxacin. This class of powerful antibiotics has been available for nearly three decades.
These cases included weakness, numbness, pain, discomfort, burning and tingling. That office also reported the case of a man who had a hypersensitivity reaction while taking Levaquin. After getting a second treatment with the drug, he was admitted to the intensive care unit and died within two weeks, according to FDA documents.
In a more recent review, FDA staff reported that this class of drugs carries a risk of cardiovascular disease, and of tendon rupture and peripheral neuropathy.
“Over the life-cycle of these drugs, several adverse reactions have been reported and most of them were not evident in the preapproval safety databases,” the FDA reviewers wrote.
WIND: note the “previously unknown” phrase, which translates to “we are incompetent and once in a while we finally fix things that hurt people”.
My own experience with metronidazone suggests to me that doctors learn about a drug in medical school, hard code the “known” issues into their brains, and then lock down their knowledge (what exactly would cause them to do otherwise?!). Combine that with a touch of arrogance (“another hypochondriac patient imagining things”), decreasing remuneration and so on. Bad combination. How else to explain my doctor emphatically answering “NO” to my “any risks” question? A google search turns up all sort of issues with Flagyl/metronidazole. How the hell does a doctor prescribe double the usual dose for double the usual time and get away with being so ignorant?
Accurate distance: I calibrate my SRM Power Control head unit by measuring distance along a long measuring tape using at least five revolutions at a specific tire pressure while my weight is on the bike as I would ride. I then divide to get a circumference good to a millimeter or so (should be ~0.05% error or so). This delivers accuracy down to 1/1000 of a mile (5 feet) using the SRM. If I ride the same course over and over, I get the same figure every time to 0.001 mile. If I change tire size (different wheel), I can immediately see the error in distance over the same course (unless I recalibrate).
I do not use GPS for any of my cycling, having found it highly inaccurate in both distance and a bad joke as far as altitude (losing 1000' all of a sudden, reading descent while ascending steeply, etc). GPS such as the Garmin Edge 500 produces garbage data under the conditions I would most need it (mountain biking with tree cover and switchbacks, but also road biking under tree cover).
Some folks ride flat open roads, and there GPS is presumably not too bad. But all those KOM things... well now IEEE Spectrum reports on GPS inaccuracy in Why Every GPS Overestimates Distance Traveled.
Runners, mariners, airmen, and wilderness trekkers beware: Your global positioning system (GPS) is flattering you, telling you that you have run, sailed, flown, or walked significantly farther than you actually have. And it’s not the GPS’s fault, or yours.
Blame the statistics of measurement. Researchers at the University of Salzburg (UoS), Salzburg Forschungsgesellchaft (SFG), and the Delft University of Technology have done the math to prove that the distance measured by GPS over a straight line will, on average, exceed the actual distance traveled.
As an example of “lab testing blinders”, the researchers (mathematicians) quoted in the article seem to be clueless about far larger errors in the real world! Their findings are laughable in the face of actual real-world errors in the opposite direction of error (too short in distance)—real world issues that relegate their findings to a rounding error!
It’s a classic case of not seeing the forest for a few sticks of wood. Their “test” consisted of having subjects walk a 10 X 10 meter square. While this validates the mathematical model (apparently), how is that realistic for anyone anywhere using a GPS to track distance? Do you walk in a 10 X 10 square, or have you ever?! Science like this which uses a context bearing no relation to actual usage conditions is devoid of knowledge.
So here is some knowledge of actual GPS performance based on real-world usage. The errors cited here dwarf the researchers mathematical masturbation, at least if the goal is relevance to the real world.
First, consider GPS ridden under tree cover, or in a canyon. The GPS signal can get spotty coverage, leading to gross errors of at least 10%. This is as real-world as it gets, and these are huge errors and I have observed them firsthand.
Consider riding a 10% to 15% grade (or even 18% for miles)—consumer GPS cannot gauge altitude with any accuracy, so it will report a shorter distance than actually traveled (because the travel is on the hypotenuse, not the shorter “leg”).
Or consider a course consisting of frequent undulating dips in the road, rising and falling 5 to 50 feet: GPS will measure that as straight-line distance (especially downhill where the descent lasts only a few second). So the distance will again be grossly in error, with greater error the steeper the slope.
Consider a step trail consisting of tight switchbacks: what are the chance that switchbacks of, say, 20-50 feet back and forth will be measured properly (and also the altitude factor, above). Particularly if the sampling frequency is too low for the time taken to negotiate the switchbacks. When hiking or bouldering where the route is constantly wavering and wandering constantly, the same sort of thing applies.
Someone should strap a GPS to Alex Honnold and see how much distance it is from the bottom of El Capitan to the top!