Why is coffee provided for free during big chess events like the Olympiad despite the fact that it contains caffeine, which is a banned substance according to the World Anti Doping Agency (WADA)?
According to FIDE's Anti-Doping Policy:
The 2018 WADA Prohibited List and Monitoring Program can be found at: http://list.wada-ama.org/ The most relevant banned substances for chess are:
• Amphetamines – e.g. Adderall, Ritalin
• Ephedrine and Methylephedrine – Prohibited by WADA when its concentration in urine is greater than 10 micrograms per milliliter
• Pseudoephedrine is prohibited when its concentration in urine is greater than 150 micrograms per milliliter
Substances not present on the Prohibited List but represented in the Monitoring Program:
• Caffeine – Included in WADA Monitoring Program and relevant for incompetition testing only. Any urine test reading of less than 12 micrograms per milliliter poses no problem.
• Codeine – A common ingredient in, for example, preparations used to treat coughs and stomach upsets. Any dosage is highly unlikely to be significant when taken in normal therapeutic quantities.
Note that caffeine is not currently banned. It was banned during the period 1984 - 2004 but was lifted. I'm guessing that sponsorship via advertising from Coca Cola may have been an important factor.
It is not prohibited would be the main answer.
Caffeine was removed from the list, and moved to the WADA "watch list", so it is not currently banned. "Bupropion, caffeine, nicotine, phenylephrine, phenylpropanolamine, pipradrol, and synephrine: These substances are included in the 2019 Monitoring Program, and are not considered Prohibited Substances." (quote taken from both the 2019 and 2020 WADA prohibited list PDF document).
"The legal limit under previous restrictions was 12 microgram/ml in urine, which is roughly equivalent to drinking 8 servings of espressos over the course of a few hours." (quote taken from nationalcoffee.blog)
Because nobody seriously considers it an advantage in chess. The WADA applies to sport, where caffeine can improve performance because it's a stimulant, thus improving physical performance. In chess, however, physical performance is meaningless, and no one has ever performed a test that proves caffeine leads to better chess (as opposed to, say, faster times in a race). Indeed, since one of its side-effects is an increase in impulsiveness, it could very well prove a detriment to playing better chess.
I can see where it might yield a minor advantage in blitz, where fractions of a second in punching the clock would matter. But in normal tournaments, I'd wait until someone actually does some testing before worrying about any substance.
OK, from the comments I see I need to add some details (in no particular order):
Java language: was called Green or Oak for most of its development. Oak was already trademarked, so they couldn't use it. Kim Polese of Sun held a brainstorming session among the development team in which hundreds of names were tossed into the discussion (James Gosling said he thinks half the words in the dictionary were named at least once). No one has the definitive origin, everyone who was there tells a different story of how it started -- good luck separating truth from retcon on that. (In fact one origin story has the group handing off a set of names to Sun's Lawyers, and they picked the name. In any case, the relationship to coffee is barely mentioned in any of the stories.)
Blitz phase: standard FIDE time controls have a 30-second increment, hardly necessitating fast clock punches.
Caffeine on performance:
Can we agree to draw a line between "physical performance" and "endurance?" The former (in chess context) is a measure of the ability to rapidly and assuredly and firmly move pieces, press clock buttons, etc. The latter relates to continuous activity. I thought that distinction was obvious; equally obviously it wasn't, given some of the comments. Again, my bad.
Relative to endurance https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752738/ is a paper that concludes, among other things, that while controlled caffeine dosages can have some effect, the dosage is idiosyncratic; pertinent quote from the abstract: "Contemporary evidence suggests current standardised guidelines are optimal for only a sub-set of the athlete population." They go on to say the effect depends upon many individual factors, which of course renders a one-size-fits-all test irrelevant. (It might be material here to note that the range they talk about as being effective equates to roughly 4-10 cups of coffee (3-9 cans of Red Bull) an hour before the game for a 100kg person. (The paper's highlighted range was 3-9mg/kg, rather an imprecise setting but there it is). Given, as I said, that caffeine is known to lead to impulsiveness, I think I'd be pleased that my opponent came to the board with, say, 8 cans in him. I'd probably pass him a couple more quite willingly.
To my mind that paper is pretty strong. Higher doses than optimum give no additional benefit, and optimum doses for an individual are unknowable without doing a workup on the individual, so precisely what benefit does the testing provide?
Of interest but perhaps limited relevance here is http://www.anusha.com/uscfdrug.htm (the USCF resolution on drug testing -- the tl;dr of it is "test if your national committees give you money, but stop thinking it's performance related, because it isn't")
We have a nebulous (extremely wide range) dosage that may cause endurance benefits in some people. Which, to me, condenses into "We can't take this seriously without a lot more research."
Caffeine is known to promote impulsive behavior, and risk-taking (a cambridge study links it with gambling addiction, brings a whole 'nother meaning to the phrase "coffeehouse chessplayer"). I'm not sure how you can translate that kind of effect into "improves chess play."
But OK, maybe "nobody cares" might have been a bit over the top. My bad. I originally wrote "nobody who's familiar with testing methods and caffeine" (which, BTW, includes WADA, who specifically do not include it on their prohibited list) but decided the generalized version would keep me from having to write a dissertation about it. Looks like I was wrong.
There are a lot of urban legends about caffeine and software (same with whisky, the phrase is "the Ballmer Peak" if you're interested). Doesn't make any of them true; a wise person views them all with skepticism.
Caffeine is not good for one's chess in any amount one would actually feel. Tt always hurt my chess. I used to go to a player's restaurant and he would pump coffee into me all I wanted and I paid. Now I'm sad to admit I have played on stronger stimulants in the past and got mixed results. If I took too much my chess was simply terrible. I was not impulsive at all. I would play too slowly analyzing. If the level was right and I was not tired it would have a positive effect on my game. The nature of those stimulants is rather transitory and one can never put their trust in such things to improve their average game. I see why the stronger ones are banned because some might get a performance boost, but it would only be a short-term kick more than anything. One thing about stimulants that are not caffeine at the right dose is one's concentration is drastically improved and one becomes more focused. It's why they give it to kids. Those that are on it shut up and maybe pay attention. Curse them for doing this to kids. Alekhine used to eat candy "A brain is not a brain without sugar." No doubt that is a better choice even if it only gives one a placebo effect.