Electrolytes Don’t Help Much?


“Drink when you are thirsty. Don’t have a schedule on time or mileage,” he said.

“Just [drinking] electrolytes aren’t going to protect you from high or low salt levels you need to eat salty food as well,” he added.

@PrecisionHydration, what say you of this study?

Unfortunately the article doesn’t link to the referenced paper. The article is too light on details and context.

Without reviewing the paper and going purely by what’s in the article, it’s not stating anything that isn’t common sense

  1. If you consume a hypotonic solution (less sodium concentration than blood should have), you’re dont have enough salt in your solution to help and are actually making the problem worse and heading towards hyponatremia
  2. Hypertonic solution will help but take too much and then your sodium levels get too high and you’re causing problems the other direction

They aren’t saying that electrolytes dont help but, rather, the wrong amount (too much or too little in solution) doesn’t help

It tells you the author, though, which is enough to find it. Here is the abstract: Effect of Sodium Supplements and Climate on Dysnatremia During Ultramarathon Running.

Key takeaway from the abstract: “avoidance of overhydration” helps prevent exercise-associated hyponatremia, and “avoidance of dehydration” helps prevent hypernatremia. Well… okay. What that really means is that on average, people’s hydration strategies are all over the map, and the level of hypernatremia or hyponatremia they end up with is also all over the map.

However, if we assume that a) yes, hydration strategies are all over the map and b) hydration requirements are all over the map, this is exactly the result that we would expect. Some people who actually don’t have issues with losing too much water or sodium to sweat are still going to overdo it, and some people who do have issues aren’t going to do enough - as well as every other combination.

I’d be interested in a study like this that attempted interventions in a non-control group - did some testing of runners’ sweat rates and sweat sodium concentrations, suggested a hydration strategy, and then observed whether individualized hydration strategies yielded better final hydration results than “all over the map.”


Hi @MI-XC, thanks for flagging this and asking for our input.

This article by CNN caught our attention too and it’s great to see there’s more research going into the area of hydration in sport.

Sorry for the delay in coming back to you, we’ve been trying to source the full paper to get the complete picture, and unfortunately it’s important to highlight that without the full paper available at this point it’ very difficult to draw conclusions from either the CNN article or the study abstract, but we do look forward to diving deeper into the methodology and results as and when the paper becomes fully accessible.

On the basis of the information we’ve got available at the moment, let’s start with the statement: “Drink when you are thirsty. Don’t have a schedule on time or mileage,

The CNN article in question is an example (one of many, unfortunately) of taking a fairly complex topic, which has many caveats and nuances, and overly simplifying it. This is a running theme in the history of hydration whereby the advice given to athletes has changed drastically over the last 100 years.

Originally, it was drink nothing at all (drinking during a race is a sign of weakness!), then it was to drink as much as you can (drink, drink, drink!), followed by you must drink only plain water and only to thirst (cue Tim Noakes).

The argument nowadays is moving more and more towards: should you drink to a plan or drink to thirst?

Some researchers, journalists and even athletes themselves take a very black and white view on “controversial topics” like these - other examples are the high-carb, low fat vs. high-fat, low carb diet debate or running shoes vs. barefoot running.

In most cases, there is a middle ground - or a ‘grey’ area - which is where we like to reside. An area where the words ‘it depends’ get used a lot. Sitting here in the grey area isn’t a cop-out in our eyes, it’s showing an awareness and appreciation that not every athlete is exactly the same and not everyone will benefit from doing the same thing.

Both of these approaches - planned drinking or drink to thirst - have merits in certain situations and we don’t believe that they shouldn’t be treated as binary options. You don’t have to choose between ‘drinking rigidly to a plan’ or ‘drinking entirely to thirst’.

We’ve been working with elite, professional and recreational athletes for over a decade now and most successful athletes do have a basic framework for their hydration strategy which they’ve honed through trial and error in training and competition but - and this is crucial - this framework is flexible enough to allow them to make adjustments on the fly.

This ‘best of both worlds’ approach is very common amongst elite performers because they tend to be more in tune with their bodies and can rely more on their instincts and experience.

Problems occur more frequently in less experienced athletes who don’t have that wealth of trial and error experience to fall back on. These individuals may benefit from leaning a bit more towards a sensible pre-planned approach, but again, building in some flexibility is key.

One important factor to certainly bear in mind is that aiming for a 100% ‘like for like’ replacement of fluid loss is not something we’d encourage because there are several confounding factors, including…

  • The rate of sweat and sodium loss can outpace your gut’s absorption rate
  • The fact that different athletes can tolerate different levels of dehydration
  • Your pre-exercise hydration status
  • The availability of drinks before, during and after exercise
  • And whether you’re only hydrating to get through the current session or you’re aiming to set yourself up for a good performance during another bout of exercise later that day or the next day

Generally, the more experience you build up, the more you can rely on instinct and intuition to guide your fluid intake.

Part of the goal of the development of a robust hydration plan should be to hone your instincts so you can become more reliant on them over time.

Despite some of the more controversial statements in the CNN article, Lipman’s conclusions at the end of the article are largely in line with what we do recommend; largely drink to thirst, and eating or adding extra salt to your foods acts as a good complimentary source of sodium.

At the risk of overloading you with information, we’ve linked to a couple of published scientific papers which do back-up the inclusion and benefit of sodium in an athlete’s diet.

Valentine, 2007 - The Importance of salt in the athlete’s diet
Del Coso et al., 2015 - Effects of Oral Sodium Supplementation on Physical Performance During a Half-Ironman: A Randomised Controlled Trial

If anyone is interested in reading more full scientific papers which show the benefit of electrolyte supplementation then please do feel free to contact us on hello@precisionhydration.com.

Thanks again for reaching out and we look forward to seeing more literature around the topic of hydration in sport.