Personal anecdotes are considerably more valuable to the individual that generalized truths. Every human body is unique and while trends and generalizations matter, they do not matter as much as empirical observed facts. Much more so in the context of personal health.
You're forgetting all the biases (& fallacies) which may or may not have affected the experience or the memory leading to the anecdote. These biases (& fallacies) are detectable or the lack of them is verifiable, with the scientific method.
I'm not denying an anecdote is not valuable to the individual. It is, for the individual who made the anecdote; not the rest of us, not the readers.
I'm also will admit I, too, use anecdotal evidence. But that does not mean one has strong evidence when they do; they don't, and neither do I.
What is this 'bullshit'? There are studies that show correlations between LDL cholesterol and risk of heart attacks (happy to show you some if you're curious).
It's true that we're still making sense of how to operationalize those observations (restrictive diet, exercise, statin therapy, etc). This doesn't make the science worthless; it's just an intermediate step in this particular area of research.
> There are studies that show correlations between LDL cholesterol and risk of heart attacks (happy to show you some if you're curious).
Why wouldn't you? It seems like it would be unambiguously helpful both in general for the thread, and specifically for your argument.
For evidence that the lowering of LDL cholesterol lowers the risk of heart attacks, though, the evidence can't just be an association between heart attacks and naturally high cholesterol, which could obviously both spring from the same cause. An association between low cholesterol diets and heart attack rates, or good evidence that statins lowered mortality would both be interesting.
Except nobody is claiming all runners need a high carb diet. If anyone actually claimed that it was that most runners would benefit from a high carb diet (I have no idea if anyone actually makes this claim scientifically).
> If we instead go with "almost all would benefit" then the anecdote is pretty good evidence against it.
No, one anecdote is not pretty good [scientific] evidence against anything.
I can give you an anecdote about how I drove through red lights multiple times. That does not mean you should follow the example.
Why not? You have no idea about the circumstances. I was actually talking about driving a bike, I was a teenager, and there was barely (if any) traffic. There's pro and cons there, but what matters is I omitted the details. Hence, YMMV. Plus, the statistical evidence is too small (sample size is one). Good luck reproducing the outcome, too.
Its the same in our runner's example. There's simply hardly any -if any- evidence presented to even make the anecdotal claim. Which still lacks any statistical evidence.
What anecdotal evidence can lead to is scientific research. But we should not conclude on the outcome yet. We must keep an open mind, accept on a method and test circumstances, and gain statistical relevance.
It is absolutely mind blowing, btw, how much 'scientific' research these days is not statistical relevant yet gets passed good grades (and yields the paper) at say college & universities. I'm not sure if its incompetence or laziness or lack of time or lack of money. I've even witnessed this first hand recently when my significant other was completing an assignment for her higher education degree which I was reviewing. Four interviews lead to a conclusion. Which, yes, is anecdotal ;)
Plenty of people make that claim, just search carbohydrate loading. The scientific reasoning is very simple. Aerobic exercise performance is limited by the rate of oxygen uptake, turning fats into usable energy takes considerably more oxygen than it does for CHO. You can in a single race/session exhaust your glycogen stores, but the supply of fats is essentially limitless. So for ideal performance you want to maximize your glycogen stores before an event, and for long ones, take additional CHO during, though rate of consumption is usually significantly higher than replenishment through digestion if you are going at all fast.
That point when you have exhausted your glycogen stores is what they call bonking. Now you can fine-tune your low carb diet to hopefully have enough glycogen at any point to sustain you through an exercise session (more realistic for running than cycling) but everyone else just eats a high-carb diet.
"most [runners] would benefit" is a pretty weak and unhelpful assertion. If we instead go with "almost all [runners] would benefit" then the anecdote is pretty good evidence against it.
