Monday, October 20, 2008

*** Game Theory at Work by James Miller

This is a fun, enlightening exploration of game theory with practical applications that you can use both in and out of the office. Among this book’s lessons are the following:
  • Never hire/date someone too eager to work for/go out with you
  • Have less trust in smokers; and more in exercisers
  • Many business people exhibit honesty not because they are moral, but because they are greedy
  • Eliminating choices can increase your payoff
  • Burning money can increase your wealth
  • Exposing yourself to potential humiliation can help you get a raise
Game theory is an approach that is rational, but that doesn’t mean that is how people do and should behave. You’ll discover that sometimes when we are irrational this leads to better outcomes, and evolution has used this fact to help you overcome a rational prisoner’s dilemma. So give yourself some credit, start playing hard to get, but keep exercising, and put out that cigarette. Read on, and you'll soon learn why.

Is it better to be loved or feared?
Imagine you fear your teenage daughter becoming pregnant . First you try to reason and urge her to be more careful. But when reason fails, parents resort to threats of disowning. Should the daughter believe you? Not if you love her… If your daughter became pregnant, she’d need you more than ever…. It would not be in your loving interest to actually carry out the threat. The manifest love thus weakens your negotiating strength. Interestingly if the daughter suspected that her parents didn’t love her, then she might believe their threat, and all of them may be better off. P9

One way trip
Cortez, conqueror of the Aztecs, employed the boat burning tactic, shortly after landing in Mexico, thus showing his enemies and potential allies that he would not be quickly driven back to Europe… No tribe would want to ally with Cortez if it thought that he might abandon his fight against the Aztecs… His promise to stay, by itself, was not believable… By burning the ships and eliminating the option of quickly retreating, Cortez guaranteed that he wouldn’t leave. P11
Another way to get a raise is to tell everyone in the firm that you will definitely quit if you don’t obtain it, and put yourself in a position where you would suffer complete humiliation if you were denied and stayed on the job… By effectively eliminating your choice to stay, your boss may find it in her self interest to give you the raise because she knows you will have to leave otherwise. P12

Out of control
Telling others that you have given up control is a common negotiating tactic… Broadcasting your lack of decision making authority makes it easier to turn down unwanted requests. P13

Giving up control by cutting off communications is another way to improve your position. You could first order your troops to fight to the death, and then leave your troops behind on an island to fight the enemy. If the enemy sees you leave and believes no one else has the authority to call of the attack, then they will think that your troops will fight to the end. P14

Brick wall
If an employee constantly pesters you for a salary increase, refusing to even listen to her demands credibly signals that she has no chance of prevailing. P15

Hey blackmailers should you go pro or remain an amateur?
Before paying a blackmailer you should examine her incentives to reveal the information. If they hate you, and would enjoy seeing you suffer, then they would likely release the information regardless of whether you pay or not… A one time blackmailer (who has no track record) would have a strong incentive to make further demands if given an initial payoff… The best way to deal with a 1 time blackmailer is probably to take your chances and not pay, or pay her off with small sums for the rest of your life… By paying the blackmailer throughout her life, you turn her into a professional and make it in her interest to be honest. P16

Motivating the workers
How could you motivate all employees with just one threat? First put all employees in some arbitrary but announced order. You tell employee 1 that if she doesn’t work hard, you will fire her. This would obviously make her work harder. Next, you tell employee 2 that if employee 1 works hard, and he doesn’t, you will fire him. Since employee 2 expects employee1 to work hard, he must work hard too. Does this again with employees 3 through N. Your employees can’t circumvent your system by colluding to be lazy because employee1 would never agree to slack off. .. The key lesson is that when you assign responsibility randomly, all might accept the chance to be punished and choose not to work hard. It’s much better to have a clear chain of punishment. P31

Survival of the vigilantes
Exhibiting insanity can enhance your threat’s credibility. Some forms of insanity in this regard are a thirst for revenge even at your own demise or detriment… Interestingly evolution may have made humans precisely irrational because of the benefits it can bring… To see the benefit of being vengeful consider a small village from prehistoric times. Imagine a group of raiders steal food from this village. A rational community would hunt down the raiders only if the cost of doing so was not too high. A vengeful group would hunt down the raiders regardless of the cost. If the raiders know of this reputation, they would rather find another village. Thus vengefulness confers an evolutionary advantage. P34

The optimal strategy to adopt with respect to legal vengeance is to convince people that you are insanely attached to vengeance when if someone did violate your legal rights you would really sue them even though lawyers are expensive. P34

Price Obscurity
Contract complications reduce the damage of price competition for similar items. When every firm uses complicated pricing schemes the benefits of undercutting your rival diminish since customers will be challenged to find the low cost provider amongst all of the complications. P48

Dominate your strategy
Is stopping at red light, and going on green a dominant strategy? Actually no it isn’t. You only want to do that if all the other drivers do the same. Same issue with driving on the right side of the road. Only works in countries where all other drivers agree to do the same. A dominant strategy is one you employ regardless of what others do. If everyone else holds their breath to the point of passing out, your dominant strategy is to breath freely, and you should do it regardless of what they do. P54

Why SF has so many gays
Most humans prioritize being able to find a sexual partner. This task can be more challenging for homosexuals since they make up only a small percentage of the population. Consequently when a homosexual decides where to live, the percentages of gays will rationally play a large part in this decision… The consequence will be that a few cities will become known for having a large gay population, gaining a reputation as a gay haven, and accelerating the process further. P93

Why money has any value
Money only has value because other people want it (it has no intrinsic value). Because so many people want it, it’s useful to have it because you can trade it for goods and services. Thus our use of money is based upon a massive coordination game. P98

Why high sunk costs can hurt you
Industries with high sunk costs are extremely vulnerable to price competition because it is rational for companies to ignore their sunk costs when setting prices… Imagine your airline always has 1 flight daily from NYC to Paris. Assume that if the plane were always full, you would need charge $400 per passenger to break even. What if your flight was only ½ full, but you could sell additional seats for $300 each? Should you fill the extra space? Yes, you’re better off with $300 than leaving it empty. Of course, since everyone in the industry will feel the same way, the market price could easily be driven below $400. P109

Balance of spam power
We have currently reached an email spam equilibrium in this country, if American spammers spam less (because we outlaw or regulate it), some users would get less sick of spam, and actually read more of it, thus increasing the benefits of foreigners (who are beyond US legal jurisdiction) to start spamming us. This would of course cause users to again ignore spam at the same rate. P110

Career criminal? Consider joining a union
Joining the Mafia would allow criminals who are arrested to overcome their prisoner’s dilemma (of ratting out their colleagues), because of the mafia code of killing rats. This added punishment changes the prisoner’s dilemma… In an effort to avoid the mafia death penalty, both criminals should now not cooperate and will thus get a lenient sentence. So Mafia membership clearly has its privileges since such membership will clearly lower your sentence if caught, and we can thus expect mafia members to commit more crimes. This gives the mafia a significant competitive edge in the market for crime. P118

Why some freak who can shoot a ball will make in 1 year more than you in your lifetime
A professional athlete like a basketball player has a very specialized talent. His skill in basketball can’t be transferred to other sports or professions. As a result, he won’t make anywhere near his basketball salary in another job… If a team offered lowered salaries, they would still attract top talent since this talent would have no other place to go. Indeed offering multi-million dollar salaries might shorten their careers because it makes it easy for them to retire early. But individual teams face a prisoner’s dilemma with respect to salaries. If all the teams offered a low salary, your team could greatly benefit by paying a higher wage and attracting the best talent. But once you do that, the others teams must counter. Offering high salaries is a dominant strategy for each team, even though they are all worse off because of it… Teams have tried to limit this dilemma with salary caps, and player’s unions fight against such caps. P125

All for 1, and 1 for all
As a soldier the best way avoid harm is to run away only if all of your fellow soldiers stayed and fought. But if everyone on your side runs with you, it will be easy for the enemy to hunt you all down and kill you. Thus, you all might be better off if everyone stayed than if you were all cowards… Armies solve this coward’s dilemma much as the mafia solves the prisoner’s dilemma – cowards are court marshaled and executed. P131

Why you should trust exercisers over smokers
Game theory teaches that when 2 people play a finitely repeated prisoner’s dilemma game, they should always be mean… Unfortunately for game theory, when real people play this game, they are often nice to each other. Why do they do this?... Many people outside of game theorists are nicer than they should be, but still don’t like to be taken advantage of… You suspect that if you play mean, your opponent will be mean back to you [the golden rule].
Like smoking, betraying someone in repeated game, helps you today, but harms you in future periods. The less someone cares about the future, the more likely he is to betray you… People’s actions thus betray how much they care about the future relative to today. You have limited trust in smokers because they obviously care far more about the present than the future. Conversely someone who exercises is willing to make sacrifices today for future benefits, and is thus less likely to betray you for a short term gain. P138

In a fixed sum game (your loss is my gain), there is no benefit to cooperating, and players will always be trapped into a mean dominant strategy. P139

Green with envy, means a red light for trust
Just as you should be less trusting of smokers, you should be less trusting of envious people. Consider how envy affects the cost/benefit calculation… Envious people enjoy a further benefit of betrayal in seeing you get a lower payoff. Since envious players benefit even more greatly from betrayal, they are more likely to engage in it. Therefore you should be less trusting of envious people, and others should trust you less if they perceive you as envious. P139

Why nice guys finish last
Having a reputation for swift and harsh retaliation is vital to being able to sustain a good outcome in a repeated prisoner’s dilemma game. Wimps can never achieve a nice/nice outcome (optimal) for their rivals will always exploit them. If others fear your wrath, the nice/nice outcome becomes obtainable since others will grasp the consequences of betraying you. P141
Imagine you buy 1000 widgets each at $10 from 2 firms, and that both firms refuse to lower their price to $6. What would happen if you started buying all of your widgets from just 1 firm and you still pay them $10 each? Firm 2 might suspect Firm 1 is giving you a discount, even if Firm 1 promised (violating anti-trust) that they wouldn’t lower prices… To add to the mistrust, you may even want to ask Firm 2 to match the new price of $6. Firm 2 would almost certainly lower its price. P146

How guaranteed lowest price can actually work against you
If a supplier gave all of his customers most favored customer status, it would be much harder for him to secretly lower his prices, because he’d have to lower prices to all of his customers. He wouldn’t be able to lower prices to just those customers he wants to steal from a rival… When one supplier issues most favored customer agreements, its rival can have much more confidence that it is not being betrayed. So even though most favored customer agreements sound like they favor customers, they really help producers by reducing price competition. P148

Don’t bother trying to find a win/win outcome if you find yourself in a one period prisoner’s dilemma. In repeated games with no last period, you should strive to cooperate. P150

So why do we tip when we travel?
I think evolution has prepared for repeated interactions amongst a small group of people where cooperation would lead to the best outcomes. Travelling amongst strangers is not the environment that you were built for. It goes against your instinct to stiff the waiter, even though that is rational.

If you want them, then they don't want you
The person a company would most want to hire would probably not even bother applying because they would be so talented that they could easily make more than the offered salary. To combat the appearance of adverse selection, a candidate should then avoid appearing overeager, and play hard to get, letting the company believe that he has many attractive offers. If a candidate is really hard to get, then a company doesn’t have to worry about adverse selection. P152 Is the same true of dating? I suspect so. If you appear too eager, your suitor may fear adverse selection, and your appeal may diminish in their eyes. So playing hard to get, yet still being gotten in the end is the way to go it seems.

Why are most used cars lemons?
Adverse selection often creates a vicious cycle. Here’s an example in the used car market… As adverse selection lowers the price of used cars, fewer used cars of excellent quality are sold, which reinforces the adverse selection, further lowering the price, which causes even more quality cars to be withheld, which causes more adverse selection…How do you break this cycle? An inspection removes the hidden information that causes adverse selection (the fear of a lemon). An owner could also provide a warranty reducing the harm of hidden information. p155
If you have to cut corporate costs by 10% is it better to lower everyone’s wages equally by 10% or to fire 10% of the workforce? Adverse selection shows you why it is better to fire. If you cut everyone’s wages, the most productive workers will probably leave to higher paying jobs. Thus because of adverse selection you’ll encourage the worst workers to stay on board. If you fire your worst 10%, you’ll be better off. P156

Why everyone pays a big deposit
If over 95% of prospective tenants in your area are honest and responsible, you may figure there is no reason to inconvenience them with a security deposit. Unfortunately if you become the only landlord to not require a deposit, then adverse selection will cause you to get all of the deadbeats. P156

Why we don't always settle a lawsuit
Adverse selection should cause me to question why you would want to settle a legal suit. You would most want to settle when your case is poor… Consequently your signal to settle is a signal that I should go to trial…Only if I learn of the strength of your case would I be amenable to your offer. P157

Why we must screen for offenders
Organizations that work with children need to be especially concerned about adverse selection even if a very small percentage of the population sexually abuses children because these abusers are attracted to such jobs that allow them to interact with children. P158

Why dictators are usually big dickheads
To gain power in a dictatorship, one must be willing to kill. It’s not surprising therefore that almost dictators have been evil scum, for most dictators would have never risen to power if they had been nice… Adverse selection also explains why most revolutions go bad, producing narcissistic, brutal regimes as in the French, Russian, and Chinese examples. The only types of people capable of acquiring power in these revolutionary environments were people skilled at murder and betrayal… Monarchies are usually superior to dictatorships because of adverse selection. A man is born king, and is therefore average in morality, while dictators are exceptionally morally bankrupt. P158

What’s the purpose of a college education?
Most people attend because it increases their lifetime earning potential. How does it do that? The standard answer is that it teaches you useful things. Signaling theory shows that college could do the same thing without teaching you a thing…. It’s somewhat hard to be accepted and graduate from a decent college… Graduating thus signals to an employer that you have a decent level of intelligence, even if you didn’t learn anything. P165

Why is race used so often to judge
Using race as a signal can be rational if race is correlated with less visible characteristics – that you can’t easily measure… Signaling theory shows that if a college discriminates against some race (like Asians) then employers might desire to discriminate in favor this race. Alas, the reverse also holds true. Affirmative action can harm racial groups to the extent that a college sends a signal of quality… Tragically, even high performing members of the protected group will be hurt affirmative action because employers could more easily judge their race than their intelligence. P166

One hand tied behind my back strategy
What if, when a rival enters your market, you stop all advertising? If your rival has any chance at long term survival, this strategy would be disastrous. If however you are so confident that no one would buy your rival’s product even when you cease your ads, then you might want to stop. Your rival will realize that if he can’t beat you when you’re not even trying, that he has no hope when you do advertise. This is similar to how a gazelle will jump 18 inches vertically when seeing a cheetah. This is a signal of fitness by displaying conspicuously an outrageous feat. P167

A warranty implies quality
A free warranty signals quality. If the product is of high quality, the warranty will not cost the seller much. The seller of a lemon would be reluctant to offer such a warranty that would impose expensive obligations. P168

Why guys are stuck buying flowers on Valentines day
Game theory forces almost all men to give flowers to their women on Valentine’s Day… Men who don’t care about their women won’t spend the money. Could a man convince his girlfriend that he didn’t need to buy flowers? Yes, but it would be like a smart person convincing his employer that he’s intelligent even if he didn’t go to college. So no flowers from your man, will leave most women thinking that their boyfriend is disinterested in them. Plus men who don’t buy flowers and are not actually interested, will often lie and claim interest. Consequently it’s extremely difficult for men who care but don’t buy flowers to convince their girlfriends that they are devoted. P170

Why playing hard to get works
If you express extreme desire to date someone, she may question why you can’t do better than her.. The strategy to adopt is to convince her that you can date better women, but you are willing to make an exception with her. Ideally, she thinks that you’d barely consider dating her. Of course if she’s a supermodel, this strategy no longer works. Expressing intense interest in that case is normal for every male regardless of your worth, so feel free to express your desires, but be coy when pursuing ordinary mortals. P171

Single women sometimes pretend not to recognize available men whom they have previously met. This is a brilliant strategy for it signals that they have so many options that they need not keep track of them all. This feigned ignorance will impress not only the men they pretend not to know, but also people who find out about their deed. And the better looking the man they pretend not to know, the higher the opinion others will have of them. P171

It’s entirely rational to lose interest in someone who responds favorably to your advances. After all this means they can’t do better than you. If they’re too eager to accept, then perhaps you should look elsewhere. P172

What’s more important – looks or personality?
Beauty may be skin deep, but it conveys information far more quickly than personality does. We are also judged not just by our appearance but the company we keep. How can you then convince someone that you are a deep, caring person? The best way is to be completely superficial in your choice of mates. What would you think of a below avg man with a strikingly beautiful woman? He must be smart, sensitive, funny and/or rich. Now what you think of the same man with a below avg woman? Probably nothing. So if you want to trade up in the dating market, be superficial. P172

If you don't label it, then they won't believe you
When a product is not labeled for a particular characteristic (lowfat, organic, safe, etc.) you should assume that either most people don’t care about this trait, or that product’s trait is bad. Even if it were average it would be labeled. If it is not labeled, it must be below average. P174

How to get out of jury duty
Juries are supposed to irrational and forget that defendant who doesn’t testify is signaling that his testimony would hurt his case (want to get out jury duty in a jiffy, just say that if a defendant doesn’t testify it must mean he has something to hide). In business you don’t have to be held to this irrational standard and you are free to assume that silence signals the worst. For example a job applicant’s resume has holes, and he is not willing to fill them in. p174

Cracking under the stress
When an interviewer asks you hostile, stressful questions he is seeing how you handle it without breaking. Or if a manager asks if anyone has free time for a new project. An unthinking person eager to the please the boss will signal their idleness. Acting quickly can reveal more about you than you want. P175

Tell your supplier that the next batch is really important, and if there are zero defects you will pay him double. If the supplier is not too sharp and complies, then you’ll have proof of his true capabilities. P175

How affirmative action backfires
It would much harder to fire a minority worker because of the threat of discrimination, thus it might be more rational to hire a white worker because he can be more easily fired. It would be worth taking a chance on the white employee, but you would only hire a minority if you are almost certain that the would be productive… Similarly it is much harder to fire workers in Europe than in the US, consequently unemployment rates are lower in the US because American firms have a greater willingness to hire and fire workers. P180

You can often use the financial aid package from one school to get a better offer from another. Make the college believe that your choice will depend upon aid; have the college believe that you are price sensitive. P185

A price for everyone, and everyone has their price
Coupons seem silly, however they effectively separate the price sensitive customers by giving them a discount by trading time for money. P187

For $130, Universal studios will sell you a pass that lets you move to the front of the lines. Supermarkets could do the same thing. They could have an express lane where you pay 10% more for faster service. They could also charge different prices during rush hour (5pm to 8pm). P189 Dept stores use this tactic by offering sales prices during working hours. Same goes for happy hours.

Company boy
Employees should always be cautious of working for a business where the experience they gain would not be transferrable to other companies. Of course, the flip side is that that you are harder to replace. P203

Credit Crisis
A governmental guarantee to banks would mean that the bank needn’t worry about lending me the money, even if you knew I would squander it, since the gov’t will pay it back. Similarly deposit insurance for a bank allows the bank to attract deposits even if the bank makes extremely risky investments. P217

Beware the hidden price of test results
If there were genetic tests that could determine when someone would get cancer or heart disease, then insurance companies would be reluctant to cover anyone how had not been tested by the company because they would fear that these folks may have been tested without disclosing the results to the insurance company. P220 Thus not having the tests makes the system work like it does today. If the tests become prevalent, and private, then insurance premiums will most likely go up to cover the adverse selection.

The most important person in the world, and why Marx was wrong
100,000 people die in an earthquake in a faraway land and it is all over the news. At the same time, you cut off the tip of your pinky finger. A close friend calls you and asks “How’s your day been?” What are you most likely to mention, the earthquake or your finger?...Communism failed because it didn’t take account this fact, that humans are self interested. P231

How the not so good, make the good even better
Imagine that Bill is better than Jane at everything at work (Bill can produce 2 widgets or 7 sprokets in 1 day, Jane can only produce 1 widget or 1 sprocket in 1 day). If you fired Jane and only had Bill what would this cost your firm? Quite a bit actually, much more than 1 widget or 1 sprocket per day. How? Through trade. Imagine your firm had to create 2 widgets, and you only had Bill left. If you had kept Bill, during that 2 day period, you could have had Jane create 2 widgets, while Bill created 14 sprockets. So the lose of Jane cost you 14 sprockets, even though she could never product at that level. Her value is that she frees up a productive resource. P238

Why art can't become too expensive
Most everyone would rather have a nice painting or art work instead of a stock certificate as an investment. Consequently if art and stocks performed equally as well, no one would buy stocks. The market automatically adjusts the return on stocks and art, such that stocks out perform. P262

More on this subject:
Thinking Strategically by Avinash Dixit
Evolution of Cooperation by Robert Axelrod
Sex and reason by Richard Posner

** Worried Sick by Nortin Hadler MD

Another doctor in the less is more camp. Hadler exposes some of the myth around treatment – especially surgical procedures and pharmacological treatment has just has not proven itself to be markedly better than no action or no action coupled with low cost treatment – such as eating a baby aspirin. He basically states that yes, we get old and eventually die, so get used to that fact. Medicine should work first to help us live as well as we can up to a reasonable age of 85 for most of us, realizing fully that even prior to that age, biological systems in our body will start to fall to pieces, and that is perfectly normal. Death is not a disease, it is a normal biological act. If you are a skeptic, this book will only harden your skepticism. If you’re not a skeptic, perhaps this will help you develop a bit of healthy questioning for your physician to ponder.

Angioplasty: case closed

A VA trial of 2000 heart attack patients had ½ receive angioplasty with a stent, and ½ not. The stent therapy did not save a life; it didn’t even spare anyone a heart attack over the next five years. The studies conclusion was that angioplasty ‘did not reduce the risk of death, heart attack, or other major cardiovascular events’ p26


Angina: is it all in your head? 

Trials of invasive procedures (surgeries) require sham controlled trial (with an actual surgery). Sham surgery trials where ½ the subjects experienced symptomatic relief whether in the sham or the putatively effective groups? That is generally the result of 1000s of placebo-controlled, randomized trials of pharmaceuticals for angina. For agents that pass regulatory muster, the effectiveness was a bit more than the 50% response rate found in the placebo group. Does this mean that angina is ‘in your mind’?... Maybe participating in a trial where you might be afforded benefit helps deal with the anticipation of the pain more effectively or allows you to circumvent precipitating angina by subtle alterations in behavior. Those are plausible forms of ‘in your mind’. For me this is reasonable enough as an explanation for the time being. P28


If you have transient ischemic attack (TIA) – a small stroke with reversible neurological deficits – and an occluded carotid artery feeding the side of the brain that is suffering the stroke, surgical removal of the plaque will afford you a meaningful reduction in your risk of suffering a stroke on that side – meaningful enough to justify the surgical risks, which are substantial. But that surgery will not improve your longevity: you are likely to die at the same time, often of stroke on the other side or of cardiac disease. P29


Angioplasty/stents: case is still closed

A large trial comparing stenting with carotid plaque removal surgery (mentioned above) had to be stopped because there were fewer deaths and strokes with carotid surgery than with stenting. There are several other trials under way using different stents and different techniques, all trying to match carotid surgery – which itself is damn near useless. P30


If one suffers a stroke, and undergoes a cerebral angiogram (a catheterization of blood vessels) within 3 hours, and has a blockage from a blood clot, then infusing drugs infusing drugs directly into the artery to dissolve the clot improves the likelihood of a more complete recovery. That assumes that you are not in the 6% of cases where infusion of the anti-clotter causes far more catastrophic than the stroke itself. I’ll take my chances with natural history and an aspirin. If stroke is my fate, it is far more likely to be mild, and to occur near my 85th birthday. P30


All tests for angina from exercising while monitoring your EKG to exercise tests that more directly monitor the perfusion of your heart muscle – are not up to making the diagnosis of angina or excluding it either with compelling validity. P32


Only 1 to 2 years is all it costs? Pass the bacon!

If you have no extraordinary family history, yet have you very high LDL and low HDL cholesterol, it will cost you 1 to 2 years of life expectancy. Nearly all who are labeled high cholesterol are far from the extreme and have minimal risk. Nearly all labeled ‘high cholesterol’ are contending with a reduction in life expectancy of months. Do you think a reduction of months in life expectancy is meaningful, or even measurable? P34


There’s no question that the ‘statin’ family of drugs can lower cholesterol… However there is a serious question as to whether statin treatment affords any meaningful advantage to those of us who have not suffered a heart attack. Are statins useful for the prevention of heart disease?... The landmark 1995 study published in the New England Journal of Medicine stated that ‘Deaths by Heart Attack’ was reduced by .6% That difference is barely statistically significant; it would happen 4.2 times out of 100 by chance, slightly less than the cutoff for significance of 5 times in 100. p35


Baby aspirin is not just for babies

The likelihood of surviving for 5 years after your 1st heart attack is 95%. If you take a baby aspirin daily, it rises to 97.5%. That’s a 2.5% absolute risk reduction, but a 50% relative risk reduction… If you have a heart attack, it makes sense to take a baby aspirin daily for the rest of your life. But should a person who has never had a heart attack do the same? The absolute risk reduction for the primary prevention of heart attack is miniscule. The good news is that the risk of intestinal bleeding is also miniscule. It’s your call. P37

Fishy conclusions about a fishy diet 

The dearth of atherosclerotic disease among Eskimos and Japanese and the fact that their diets are rich in seafood, was held up as more than just coincidence. No ones seems concerned that these are genetically distinctive populations living in countries with distinctive socioeconomic structures. The notion of eating fish or olive oil or more vegetables, or less meat or whatever promises the fountain of youth – easily gain credibility. To test the inference with a randomized controlled trial seeking differential effects on important outcomes in a well population is prohibitive. Can you imagine controlling the diet of ½ of the sample for decades, and waiting to see how many die and how? Even modern epidemiology has no such hubris… Take for example the famous Nurses Health Study started in 1976 until 1994 measuring over 120,000 nurses. During this period there were over 500 deaths ascribed to heart disease, and 1000 non-fatal heart attacks – that equates to only .5% death rate, and 1% had suffered a non-fatal heart attack. Even if every one of these 1500 women avoided fish (unlikely), and the remaining 98,500 women ate fish often (again, unlikely), you’d still be skeptical that eating fish can save lives because you’d wonder what else was going on that you weren’t measuring. P60


Are transfat really proven to be that bad? 

Trans fat are new demons of the food kingdom. How did that come to pass? From the Nurses study. There was a 33% relative risk increase based upon a tiny number of nurses whose dietary intake over 2 decades is at best approximated… Do you really think any of us can recall our dietary intake last year with the exactitude prerequisite to the analysis? P62


Want to get rich? 

“There’s a $1000 bill in every American rectum; you just have to get up there and get it.” How British doctors views the American medical system’s handling of colon care. P67


The 60/40 about 50

About 1% of people over 50 have at least 1 polyp, and the population acquires polyps at the rate of 1% per year after age 50. We also know that age 50, you have a 2% chance of dying from colon cancer over the next 30 years. You also have a 60% chance of dying from all causes over the next 30 years; or that is saying you only have a 40% chance of making it to your 81st birthday. Suppose you reduce a person’s relative chance of dying of colon cancer after age 50 by 60%. This means your 2% chance of dying from colon cancer is now .8%, but you chance of dying from all other diseases is not meaningfully reduced. P70


Breast cancer screening facts

A Canadian trial enrolled 50,000 women age 40 to 49, and 39,000 women age 50 to 59 between 1980-85. All were examined and then instructed how to perform breast self examination. They were then randomized to a group annual given an mammogram, and those who were not screened. There were 3 telling observations:

1) 213 of the 40 to 49 year olds had died of breast cancer, and the deaths were distributed equally amongst the mammography and non screened groups.

2) There were 107 deaths by breast cancer in the 50-59 group who received mammography, and 105 in the non-screened group.

3) Based on these data several – but not all – North American medical bodies have backed down from recommending mammographic screening in women aged 40 to 49. p90


To be screened or not be screened? That is the question that Hamlet should have asked. 

Almost 90% of male physicians aged 50 and older, and nearly all urologists have had a PSA (I have and all is well thank goodness). The author, who is a physician over age 50 will not consent to a PSA, let alone a rectal exam. Here’s why. Screening is defensible if most, if not all, of the following goals are met. 1st screening must detect something that is meaningful to me, 2nd it must be efficient in the sense that it has few false positives and negatives. And 3rd, if a true positive is detected, something meaningful can be done about it. Screening for prostate cancer fails on all counts. P96


No one should think that surgery will vanquish their risk of death from prostate cancer; it will only reduce it by half. And no one should think that surgery will increase your lifespan; it will only change the cause of death. P99


The cure is worse than the disease

15% of those who undergo prostatectomy will have to cope with incontinence by wearing a diaper. That’s a catastrophe for most. 30 % of men will be afflicted with erectile dysfunction, leading to distressed intercourse. That is a catastrophe as well… The men who forgo surgery are not spared, but rather suffer from obstructive symptoms impinging urine flow. P99


Prostate surgery might be worth it if you're under 65

After 10 years, 8.6% of men who had prostatectomy had died of cancer compared to 14.4 in the watchful waiting group. However overall mortality was 24% in the surgery group vs. 30% in the waiting group. There is then a suggestion of meaningful survival benefit of surgery in men younger than 65. p100

Knee jerk surgery?
Arthroscopic surgery for knee pain has been debunked in a randomized, controlled study published in the NE Journal of Medicine suggesting that you would be WORSE off for that effort. Glucosamine/chondrotin concoctions are marginally useful at best in studies paid for by their hawkers… Total knee replacement is neither a replacement nor an appealing option. Few enjoy the dramatic pain relief that those with hip replacements often revel in. P119

Let nature take care of the pain in your neck
If you neck pain be wary of vertibular surgery. This surgery is based upon theory that has never been put to the test, and is based upon extrapolating surgical outcomes for low back (sciatica) pain, that showed that surgery provided some additional relief (not much) compared to the natural rate of healing. P120

Is it better than aspirin?
The following is true of every NSAID that has ever been approved:
1. It has been shown to be more effective than placebo
2. None have been shown to be LESS or MORE effective than aspirin
3. None have been shown to be SAFER than aspirin p125

Living the high life?
25% of us frequently experience alternating diarrhea and constipation, but very consider this worrisome. As many as 20% of us find our joints stiff for 30 min or more without finding that bothersome… 5 to 15% of people are coping with being out of sorts (pain, fatigue, GI distress, etc). Most perceive themselves as no longer well, and they are particularly likely to see medical care repeatedly. P136

A bone to pick
Our bones continue to grow in fine structure, gaining mineralized matrix well into our 3rd and 4th decade…. There is a positive influence of moderate weight bearing exercises on the degree of mineralization and a negative influence of being too thin (low weight) and of smoking… In our 5th decade we slowly come to lose our bones via demineralization. This is normal. P155
Hey pinhead, acupuncture is all in your head!
Patients were saw an acupuncturist twice weekly for 10 sessions. ½ were given sham acupuncture with a sheathed needle. It looks and feels like the real thing, but never pierces the skin. Everybody improved in both trials… Further, a placebo was compared to sham acupuncture which improved pain at a faster rate than the placebo. A placebo pill is no match for the acupuncturists treatment act: the rituals, the beliefs, the body language the explanations, and whatever else went on even though the needle never pierced the skin. P195

The less than 2% solution
Here’s a partial list of treatments that would not qualify that would not benefit 1 in 50 people who are treated:
Coronary bypass, angioplasty, stents, arthroscopic knee surgery, any surgery for backache, statin therapy to reduce cholesterol to save lives, newer antidepressants for situational depression, PSA screening and radical prostatectomy to save lives, screening mammography to save lives, many a cancer treatment to save lives.

Only 25% of the hazard to longevity resides in the proximate cause of death (Lantz et al 1998)… and the lack of healthcare accounts for only 10% of our mortal hazard (Schroeder 2007). P231
615 coronary events occurred among 13,000 study participants. The poorest whites were 3 times more likely to be afflicted than the richest whites; for blacks this hazard ratio was 2.5. p232
People of low socio-economic status (SES) who resided in wealthier neighborhoods had a higher mortality risk than people of low SES who lived in poor neighborhoods… It turns out that social hierarchy influences the health of primates, including humans. It other species, it can be shown that low ranking in a dominance hierarchy associates with numerous adverse biological outcomes.

Thursday, October 02, 2008

*** Brain Training for Runners by Matt Fitzgerald

As a life long, avid runner, who has logged enough mileage to circumscribe the globe (at the equator mind you!), I thought there can't be too much more to learn about the subject of running. Well, I was very wrong it seems. The thing I liked about this book, it that it brings up the evolutionary history and the biology of running, and buttresses that with studies (science rules!), to create convincing arguments to at least try what is being proposed here. I am in the middle of altering my stride by following the precepts of this book (since I have became an overstrider in my 20s for my marathons, but when I was young and running track in High School, I was not). I have not yet raced with these insights, but I plan to determine if they indeed can boost my performance, and reduce my pain and injury suffering. For all runners a great read!

The wall is not solid
When you hit the wall, you don’t actually run out of glycogen or ATP. Exercise depletion of ATP has never been shown to exceed 50%. Fatigue in prolonged exercise is supposed to be caused by glycogen depletion, but in reality there’s always glycogen left over in the working muscles of exhausted. If total glycogen depletion ever did occur, ATP depletion would soon follow because glycogen is a source of ATP replenishment. And if ATP depletion ever did occur, the result would be muscle rigor – that is the working muscles would become locked in a state of contraction or paralysis. I doubt you’ve ever seen this happen. P47

Runners routinely begin to experience fatigue and slow down in the latter stages of a race, only to find the wherewithal to sprint the final straightaway. According to the catastrophe theory of fatigue (hitting the wall), this phenomenon is impossible. P49

The average adult stores 500g of glycogen (400g in the muscles and 100g in the liver), as compared to 12 to 18kg of fat. Glycogen supply becomes a performance limiter when runners try to maintain a fairly aggressive pace for an extended period, this is because glycogen supplies energy faster than fat, so the higher the intensity, the more the muscle have to rely on glycogen. P54

Over 80 means that it is too hot for your best time
Only 25% of the energy that the muscles release during running is used for muscle contractions. The other 75% is lost as heat… When air temperature exceeds 78F, heat accumulates in the muscles and contributes to fatigue. P55

And it can be dangerous
Hot weather racing is the only circumstance in which the brain’s self protective fatigue mechanisms sometimes fail to prevent runners from seriously harming themselves… Elevated core temperatures accelerate nerve impulse transmission, potentially causing the protective inhibition of muscle activation to lag behind motor signals ordering continued work at the same intensity. P56

Spring in your step
Few runners realize just how much energy they are able to reuse thanks to the spring effect in their joints and muscles. Research has shown that runners consume oxygen at a rate that is sufficient to produce only about ½ of the energy needed to run at any given speed. The other ½ is provided by the spring effect. P86

Think short and quick
The best runners tend to make shorter strides and hence have a higher stride rate at any given speed than average runners. P87

Unstable at any speed
When the foot lands in front of the body (overstriding) there is a lack of stability. To understand why, perform the following test. Stand normally, and then lift one foot off the ground. Is it difficult to balance? Not terribly. Now stand in a split stance with one foot half a pace in front of the other. Lift your rear foot off the floor. Can you balance in this position? Impossible. Your point of support is not aligned with your center of gravity. P87

A brake in the action
When your forward leg is reaching ahead on footstrike (overstriding common in heel strikring), the impact forces that travel up your leg move backward against your direction of travel. By contrast, when your foot lands underneath your hips, the impact forces travel up more your leg more or less straight, neutral to your direction of travel. To minimize the braking effect of overstriding, runners unconsciously try to land softly. Unfortunately, the softer you land, the more ‘free’ elastic spring energy you waste, because it dissipates before you can use it. P88

Changing your stride:
Ballistic Action
Many distance runners believe that the ideal pattern of muscle action is sustained and gentle. The idea is to use energy evenly throughout the stride, landing softly, staying relaxed, and avoiding wasteful peaks and valleys in muscle work. In reality, the best runners have a ballistic style of running. They contract their muscles extremely forcefully – much more than avg runners – during a small slice of the overall stride that begins in the moment of bracing for impact, continues through a brief ground contact phase, and terminates at push off. This anticipatory tensing is a major factor in creating the stiffness that enables the capturing of elastic spring energy. The best runners then relax their muscle as they float in the air between footstrikes and they spend more time floating between footstrikes because they are faster. P88

½ the energy we use to run goes toward simply preventing our joints from collapsing to the ground each time our feet make contact with it… If you watch avg runners you will see that they tend to bend the knee of their support leg more on impact and also that the hip of the unsupported – swing – leg dips toward the ground while support foot is planted, and you’ll notice that pelvis tips forward on impact. These excessive joint movements waste a lot of energy and put extra strain on the joints leading to pain and injury… Overstriding is a major cause of joint collapse. When your foot lands in front of your body, your muscles are not in a good position to absorb the impact. By the time your body has caught up to your foot, these forces will have had time to pull you toward the ground at your most susceptible points: knees, pelvis, and hips. P89

One of the most problematic asymmetries is long axis rotation or twisting of the spine. This tends to develop in runners who are not able to begin the thrusting (pushing off) phase of the stride until late in the stance phase, when the body has already passed ahead of the foot. To make up for the inability of the muscles to develop adequate force, the runner must keep the foot in contact with the ground for an extra last moment push off. And to keep the foot on the ground, the runner must rotate the pelvis in the direction of the trailing leg, making this leg longer. To compensate for this movement, the runner must through the opposite shoulder forward, twisting the lower – lumbar – spine in one direction, and the upper – thoracic – in the opposite… Top runners run with their hips and shoulders more square to the direction of travel. They are able to keep their pelvis fairly neutral by generating thrust early, when the foot is still underneath the body. P90

Cues to help change your stride
Falling forward
Tilt your whole body slightly forward as you run. Don’t bend at the waist. Tilt from the ankles… This cue will help you correct overstriding because while leaning forward your feet will naturally land closer to your center of gravity. P92

Navel to Spine
This cue will activate the deep ab muscles that stabilize your pelvis and lower spine, by pulling your bellybutton inward toward your spine.

Running on water
Imagine running on water without falling in. To do this you must apply maximum force to the water in minimum contact time. Run quickly, lightly, yet forcefully. This will stiffen your stride, minimize ground contact, and begin the thrust phase earlier.

Pulling the road
Imagine running on a huge rug, and you are pulling the rug behind you with your feet as you thrust forward.

Think about thrusting your body forward not upward. Imagine running underneath a ceiling that is only 2 inches above your head. This cue reduces vertical impact forces.

Pound the Ground
Running speed is almost entirely a function of how forcefully you hit the ground. The typical overstriding runner lets his foot fall passively to the ground with each stride. Instead drive your foot into the ground. If you are a heel striker, work on landing flat footed before attempting this.
Drive the thigh
Drive the thigh of your swing leg forward more forcefully than normal. This will create a counterbalancing backward-downward action in your opposite leg.

Floppy Feet
The foot contains 27 bones and dozens of muscles and ligaments. This complex structure allows the foot to deform in an intricate wavelike pattern while it is in contact with the ground. Unfortunately shoes greatly restrict this natural movement. To overcome this, concentrate on running with relaxed – floppy – feet. Continue to strike the ground forcefully, but use the muscles of your upper leg to generate this force while keeping the foot relaxed. P94

Butt Squeeze
The instant before your foot makes contact contract the muscles in the hip on that side of your body and keep them engaged through contact with the ground. This will minimize long axis rotation.

Feeling Symmetric
Compare the feeling of your arm and leg swing on your left side with that of your right side. If there is a discrepancy, adjust your stride to eliminate or reduce it.

Axle Knees
Imagine an axle or dowel pushing your knees about a ½ inch apart than normal. This engages your hip flexors and external hip rotators preventing the thigh to twist the knee – a common cause of injury.

Running against a wall
Imagine a wall in front of your nose. Your knees and feet will knock into this wall unless you shorten your stride and place your feet under your hips. Leaning forward at the ankles will create more room to drive your thighs forward as well. P95

Technique Drills
Running with no arms
Lace your fingers together and make a big circle at shoulder level like a basketball hoop. Run 100 yards at moderate speed with your arms out in that position (looking like a dork!). This will activate your deep ab muscles to maintain upright posture and teach you how to feel and activate those while running.

Steep Hill Sprints (my favorite!)
Run ballistically and fast up the steepest hill you can find.

One leg hop
Run as fast as you can on 1 leg for 20 seconds. This increases your forward push off power, and enhances hip, pelvis, spine, knee stability by forcing these joints to stabilize extreme impact forces for a short period.

High Knees
Run with an extremely exaggerated knee lift for 30 seconds. This drives your thigh forward, and strike the ground with greater force.

Run with long, leaping strides for 30 seconds. This enhances push off power and retracting your lead leg before impact. Bounding teaches you to reduce the braking effect from overstriding.

Stiff Legs
Run for 20 seconds with your knees locked. This helps your feel your buttocks and decreases your hamstrings for forward movement, improving stiffness. P97

Where or where are my deep abs?
The deepest muscles of the abdominal wall (transverse abdominis and internal obliques) are vital to proper stabilization of the pelvis during running. Yet the vast majority of runners, including elite runners, are unable to activate these muscles to maintain pelvic stability. This results in energy waste, and increased risk of overuse injury. Weakness is not the issue. It only takes 10% contraction of deep abs to do the job. Rather it is a problem of neuromuscular communication. Our brains literally cannot find these muscles, probably because of the absurd amount of time we spend slouching in chairs. P101

Why we get sore
Most of us associate inflammation (swelling) with acute injuries such as an ankle sprain. But a much milder inflammation response occurs after normal workouts in which we do not suffer any serious injuries. Every workout causes microscopic damage to muscle fibers, which are repaired with the aid of inflammation during the following recovery period. The main cause of muscle damage are lengthening contractions such as the lowering phase of a bicep curl when gravity is pulling the weight down, but the contracted muscle is resisting. In running a similar thing happens during the footstrike, when the quadriceps are forced to lengthen by impact forces but contract to absorb these forces and prevent joint collapse. P141

And why it hurts worst 2 days later!
Inflammation from muscle exercise produces chemical signals which begin 2 hours after a workout and last about 48 hours… Inflammation promotes satellite cell proliferation, a step in developing bigger, stronger muscle fibers, and it protects (even after 1 workout!) muscles from further exercise induced damage. P142

There is a negative side to inflammation, it also causes secondary muscle damage between workouts from the release of free radicals. Secondary muscle damage is the main reason you feel sorer the morning after, and why you sometimes feel sorest 2 days after a workout. This soreness does impact your performance, in trained runners, it reduced running economy by 3% (which is significant because a lifetime of training may only boost your economy by 10%). P142

Science behind recovery runs
It is widely assumed that the purpose of recovery runs (slow runs undertaken 4 to 24 hours after a hard run) is to facilitate recovery from the preceding hard training. You hear coaches talk about how these runs increase blood flow to the legs, clearing away lactic acid, and so forth. The truth is that lactic acid returns to normal within 1 hour even after the most brutal workouts, nor does this acid cause fatigue in the first place, nor is there any evidence that light activity promotes muscle repair, glycogen replenishment or any other physiological response pertinent to muscle recovery. Why then are recovery runs then universally practices by top runners, and what are the real benefits? There’s a cytokine Interleukin 6 (IL6) that is released into the bloodstream by the muscles during exercise and travel to organs throughout the body, including the brain. Increasing levels of IL6 in the brain cause fatigue. In an experiment, runners injected with IL6 run a full minute slower than those given a placebo. IL6 is believed to facilitate many of the body’s adaptations to exercise training, ranging from increased fat burning to greater resistance to muscle damage, to improved cognition. The primary trigger for IL6 release during exercise is glycogen depletion… Thus training in a glycogen depleted state will tend to produce more IL6 than a non-depleted state. Research backs this hypothesis: Subjects exercised one leg daily, and the other twice every other day. The total amount of training was equal for both legs. After several weeks, the twice trained leg increased its endurance by 90% more than the once daily leg. P150

The release of IL6 is probably not the only mechanism by which recover runs enhance fitness… The brain also tries to avoid worn out muscle fibers and instead involves fresher fibers precisely because they are less preferred under normal conditions. When your brain is forced out of its normal pattern, it find neuromuscular shortcuts that enable you to run more efficiently. Another benefit is that seldom used fibers now become conditioned to prolonged running. They adapt to these demands by producing more mitochondria, capillaries, and aerobic enzymes, so they can be more helpful when called upon again. P151

Sitting is your enemy
The average office worker spend 9.5 hours sitting per day… A study showed that folks who spend more than 7 hours sitting/day are nearly 70% more likely to be overweight than those who spend less than 5 hours sitting. P173

The deep abdominal muscles wrap like a corset around the midsection of your body, to help you maintain upright trunk posture and stabilize the pelvis and lumbar spine during activities. When you sit, you don’t use these muscles, consequently they become weak. Instead it is the hip flexors, muscles that cross the hip joint in front of the body, do the job of keeping the trunk upright while sitting. As a result of using our hip flexors for hours each day, they become really tight because the brain spends so much time providing low level activation of these muscles that it loses the ability to fully relax them. Tight hip flexors create problems for body alignment by causing a forward tilt of the pelvis, this causes your center of mass to shift forward too, so the body compensates by tilting the pelvis forward and arching the lower back. This compensation puts a tremendous strain on the hamstrings, which become active in pulling the pelvis down on the rear side to correct the forward tilt. As a result, the hamstrings become tight. And finally, sitting requires that you relax the buttocks and outer hips, so these muscles become weakened. All of these imbalances can lead to running inefficiencies and injuries. If you have tight hip flexors you are unable to fully extend your hips at push off (you should achieve a 10 degree backward extension of the hip). If you can’t do this, then you can’t completely use your strong extensor muscles – your buttocks and hamstrings – to generate thrust. In addition, tendonitis of the hip flexors is common. And weak quads are commonly implicated in runner’s knee – the most common running injury. .. Finally, excessive forward pelvic tilt contributes to lower back pain. P175

The overstriding epidemic
80% of runners overstride and land heel first (I’m one of them!), but when barefoot, exactly 0% of runners overstride. Why does this happen? The heel of the foot contains nerves that transmit information regarding the hardness of the surface and force of impact. This helps the brain decide whether to adopt the walking or running gait. A slower pace with less forceful impacts will help the brain determine a walking gait is appropriate. Cushioned running shoes produce a softer impact at any speed, so the brain develops a hybrid walk-run gait with a heel strike. This is somewhat speculative. The rigidity of the shoes also prevent the foot from deforming upon ground contact in a natural wavelike pattern compared to bare feet. As a result impact forces are sent shooting up the leg, concentrating in the knee, hip, pelvis and lower spine. P182

Rinse, repeat
In one cycling time trial of 1 hour duration, subjects rinsed their mouths with water (no swallowing) every 7-8 minutes. The same subjects repeated the time trail after some time. This time they rinsed with a sports drink. They completed the trial almost 2 minutes faster with the sports drink. Somehow the carbohydrate in the drink affected the performance without ever reaching the bloodstream. How did this happen? There are carbohydrate (sugar) receptors in the mouth that communicate with the brain, which stimulated the brains ability to recruit muscles by fooling the brain into believing an source of energy was available, making it safe to work a little harder. P189

It's all in your head
Older studies have show that when endurance athletes are given a carb drink at the start of the race, they go faster from the very start when compared to be given water. This flies in the face of conventional exercise wisdom, which holds that consuming carb drinks enhances performance by delaying muscle glycogen depletion… If this were true, then athletes would not go faster from the very beginning, they would merely continue longer. The fact that they go faster suggests a brain mediated factor is at work. P190

Obey your thirst
There is a prevailing belief among nutritionists in and out of sports that the thirst mechanism is unreliable, and that we should drink water at regular intervals to avoid dehydration. This is because the typical voluntary drinking rate during vigorous exercise is only 70% of the rate of body fluid loss. On the basis of this observation and the presumption (not proven) that any amount of dehydration is detrimental to performance and health, scientists decided that you should drink ahead of your thirst. As it turns out, an abundance of recent research has demonstrated that the negative performance and health consequences of dehydration during exercise have been greatly overblown. In fact, the negative consequences of drinking too much appear to be greater. P191

Dehydration seldom causes runners to overheat. Instead it is overexertion in a hot environment. In hot (especially humid weather), excess body heat doesn’t dissipate well, and it accumulates in the body… Interestingly, hot weather racing is the only circumstance where the brain’s self protective fatigue mechanisms fail to prevent serious harm. Elevated core temperatures accelerate nervous impulses, potentially causing the protective inhibition of muscle activation to lag behind motor signals ordering continued work at the same intensity. P192

Runners who attempt to hydrate as fast as they lose fluid encounter gastrointestinal distress, due to the jostling of the gut, and the slower rate of gastric absorption during exercise. P193

During running urine production decreases by as much as 60% due to increased blood flow to the muscles. This traps excess water in the tissues… Drinking too much during prolonged exercise causes blood sodium levels to drop. This will cause your tissues to absorb more water in an effort to restore the sodium level, and thus lower your blood volume (just as dehydration). So overhydrating while exercising is not good strategy. P194

The typical elite marathoner drinks only ½ a liter per hour while sweating 2 liters per hour, and the higher the finisher the more dehydrated and the higher their core temperature on average… The lesson we need to take from the top runners is simple. It’s better to trust your thirst and drink only as much as you can tolerate while running as fast as you can than it is to slow down to drink more or risk GI distress. P195

It’s important to bear in mind that our ancestors had no way to drink on the run while chasing prey (or being chased!). They had to run for long stretches without stopping to drink, and when they did drink, they had to stop. So while there was a strong pressure toward the ability to continue running despite heavy fluid losses, there was little or no selection pressure toward being able to drink effectively while running… It is interesting to note that training has no effect on the rate at which the stomach and small intestine absorb fluid during exercise. The digestive system is one of the only parts of the human body that does NOT adapt to exercise training. P197

A little protein goes a long way
15 cyclists rode stationary bikes to exhaustion twice on 2 separate days while drinking either Gatorade or a protein laden sports drink. The cyclists were able to ride 29% longer in the 1st ride and 40% longer in the 2nd ride when drinking the protein drink. They also found that the protein drink reduced muscle damage by 83%... This study has not been successfully duplicated, however, drinking protein drinks has equaled or bettered endurance performance in every study when compared to a carb only sports drink (ie. Gatorade), and the reduced muscle damage claim has been confirmed in every study designed to measure this variable. P198

Researchers are still trying to figure out how protein consumption reduces muscle damage during exercise. The simplest is that protein provides an extra source of direct energy that substitutes for muscle protein, because scientists now recognize that the body relies far more heavily on protein for energy during intense and prolonged exercise than was previously thought… Another possibility is that elevated blood amino acid levels that occur when protein is consumed during exercise act as a brain signal that reduces muscle breakdown. P199

What to drink?
Given the established performance boosting effect of carb drinks, you might assume it would be a good idea to use a sports drink during every run (I never use them and would prefer to indulge in getting my calories in another, more pleasurable form). New research suggests that intentionally underfueling the body during workouts may trigger a more pronounced fitness boosting adaptive response. The rationale centers on IL6… The primary trigger for IL6 is glycogen depletion, so it follows that training in a glycogen deleted state will tend to produce stronger training adaptations (remember recovery runs?). Studies have shown that muscles produce much less IL6 when carbs are consumed during exercise… Given this, it’s reasonable to ask if whether runners should underfuel themselves in every workout… Studies have shown that athletes who consume carbs during workouts are able to handle higher training loads than those who don’t, and are able to perform at a higher intensity. Consequently, the best training recipe is probably a mixture of fully fueled and underfueled workouts. P201