How do we know something is true?
I don’t want this to be a post about life, the universe and eternal verities – this is after all a running blog – but it is important to know that advice we receive is well founded. It is important to know that any science has been accurately reported and translated and the sources can be checked. If advice is based on experience then that experience must be directly described with all the circumstances to allow the reader to separate the more general lessons from the particular, individual instance. Then we can make judgements.
Sometimes, however, I worry that things are assumed to be true just because they are frequently repeated. Take hydration – apparently you should drink 2 litres of water (and only water) a day otherwise you risk chronic dehydration. This is an example of that sort of assertion from the BBC website. I know this is not a from a sports site and the article drifts off into something that should be savaged in ‘Bad Science’ in the Guardian ( I particularly enjoyed the electromagnetic memory of water and the idea of implosion research has a sort of charm), but I have seen similar water advice in a number of places.
In particular there is a lot of anti-caffeine prejudice. As someone who mostly drinks a mixture of coffee, tea and green tea I find this very tiresome. I have drunk like this most of my adult life and have not become progressively dehydrated and shrivelled like a prune (although my brow is rather too furrowed). My favourite recovery drink after a long run is a big mug of tea and I don't want to change that – so I will continue according to the motto that if experience contradicts the theory; stick with the experience.
However there is no contradiction. This article on the urban myths site Snopes seems to be the sort of balanced assessment I like - it means I do not have to change my ways. The worrying thing is that it cites a self-published book as the main source of the myth about chronic dehydration. How can such a publication have such a big influence?
One of the consequences of the Internet is that it allows rumour and speculation to be passed off as fact because of a weight of repetition. Alomost anything can spread like a virus. It is thus increasingly important to check sources and always ask: how do I know this is true?