I am currently reading an excellent book by a surgeon, Atul Gawande, called complications in which he talks specifically about how and why complications occur in medicine but also calls extensively upon evidence from other areas of society in particular industrial processes and aviation.
Clearly if you are responsible for the safety of others, such as the CEO of an airline you want to know you pilots and planes are as safe as they can be and that you are going to "minimise" the risk of any "incidents". Airplane crashes cost lives and business, and as a consequence the aviation industry has some of the most complete process analysis of risk and an understanding of how to minimise this risk. The weak link in this is usually human beings. Protocols are no good if they are not read, taught, understood and applied. Human beings may also do all of these things but unlike a computer may decide to ignore them, forget them or remember them incorrectly.
The challenge in medicine is that the range of variables you have to account for are far greater than those that affect the aviation industry, but even where there are well defined protocols and limited variables, Doctors will often go with their gut instinct when making a diagnosis. Now your gut instinct may well be quite good as it generally represents your subconscious brain representing your experience and knowledge from previous similar situations. However the evidence suggests that where we vary dramatically from standard diagnostic protocols we are more often wrong than right. In other words we should go less with hunches and more with evidence- and computers give us that evidence. Computers diagnose heart attacks on an ECG more effectively than humans- fact. Computers (when fed with the right data) are more accurate at diagnosing appendicitis than humans- fact.
So why is it that humans often continue to go on with a pattern or process that if they viewed the evidence more carefully they would realise is the wrong decision? This has something to do with what drives human behaviour. Anthropologists would have us believe that whilst many of us are happy to go with the flow or follow process it is the rebels amongst us who choose to do things differently that are exhibiting the human traits that have made us the most successful* species on the planet. It is the rebels that take risks that can find new advantages in the ecology thus increasing their likelihood of procreation and survival (before we all got sophisticated and started wearing Lycra).
However as we start to get a greater and greater grip understanding of the science of a whole range of situations the advantages of the "rebels" start to be lost to those who are most adept at understanding and applying the science.
So finally we get to triathlon. It has to be said that most of the knowledge of training and exercise is based upon very poor science. If you want to know whether training regime a or b is better you need to get a large number of similar talented triathletes. Get them all to train strictly to either of the two regimes and then test them all in an equivalent valid test at the end of the raining process. Given everything we know about what affects performance including periodicity, diet, general health, weather and god knows what else the trial would have to include hundreds in each training regime to give us reliable evidence. so currently a lot of training is not based around science but about "gut feeling and experience" based on a coaches previous observation of the effect of training and their outcomes.
This is still a long way from the optimum but you can see how the "science" is starting to creep in such as in this post on the EC post how the scientific knowledge can be used to predict a certain level of expectation. So lets here it for the barefoot funning.... the science suggests that it is a quick root to injury for many and there is no evidence it helps you to run faster. But is that the point?