Drinking Water while Running…

On Wednesday I was invited to an event at the Sports Science Institute as a thank-you for the research project I took part in during the Comrades.  Tim Noakes was one of the speakers and he had some very interesting things to say about the theory that says if you drink too much water, it leaches your system of all the electrolytes,  basically putting your body  in great danger.

Now I’ve always believed this theory – I never knew where it came from and I guess I just believed it because it sounded pretty logical to me, however Prof Noakes explained using his research findings and a very clever slide show – that this theory had absolutely no scientific grounding and was really just part of a marketing ploy hatched by Gatorade and its scientists (who just happened to be the same scientists who advised the US Army on liquid consumption and what the daily recommended allowances should be).

I’m totally simplifying many years worth of work here but it was fascinating to see how a theory can develop and become ‘common knowledge’ without anyone even questioning it.  Prof Nokes went on to say that the human body is incredibly clever at making sure there is balance  – the balance of water and salt being very important for runners performance – or so we thought…

Science has proven that it is virtually impossible to leach the body of salt, our bodies are constantly trying to get rid of the salt we consume (in excess) so this is something we don’t need to worry about.

He also pointed out that our bodies evolved in such a way that conserving water is something which it does exceptionally well – so if your body realises it is going to be exercising for long periods of time without any water, it recalculates to make sure that there WILL be enough by curbing urination and sweating – the bottom line being, drink when you are thirsty, not according to some ‘rule’.

Prof Noakes concluded by saying that the only thing which plays a role in enhancing performance, is carb intake  – so as long as you are consuming enough carbohydrate to keep your energy levels up, you shouldn’t have to worry about water.

Makes you think a bit about the other ‘theories’ which we believe when it comes to long distance running, doesn’t it…

waterPhoto Credit


  1. Cands says:

    Hi Julie, thanks for the comment! Good luck with the Boston marathon – it is definately on my list of marathons to run… Keep in touch!

  2. Julie says:

    I just found your blog and really like it! You are a much more experienced runner than me. I’m currently training to run my first marathon (Boston in April) to raise money for charity. Thank you for this awesome post about water, salt, and carbs. I was very confused about all this, but your blog post cleared things up for me. Happy Running, Julie (Blogging about my experience training for the Boston Marathon at: remrunner.blogspot.com)

  3. Philip van Gass says:

    Candice I have heard that overhydration can occur in long distance runners although it has never happened to me. So did the Prof make any distinction between this and ‘leaching of salts’ as you put it. If so what are the symptoms of overhydration ?


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