Reaction to the ‘Sports Drink Debate’ Article

A recent article by Paul Laursen on Trizone alluded to the dangers of drinking too much during an iron distance triathlon.

Great advice from Paul! Hyponatremia is a serious medical condition and every endurance athlete should be aware of it. While reading this article it is pertinent to ask the question. Who is this article targeted at? The article specifically mentions ‘slower athletes’. Why are ‘slower athletes’ more susceptible to this medical condition? Is it because they follow a similar hydration strategy to athletes who are not on the course for near as long?

We had a lot of correspondence from some serious players in the sport of triathlon on it. One of the main areas of interest was about taking extra sodium while racing.

Last year at Kona Crowie was very specific about the role a lack of salt played in his race. We also learned just how long Alexander had to deal with cramps on the course that day – it turns out the last four miles of the run was a struggle.

“There’s always a part when you start cramping,” he said. “I ran out of salt tablets. I felt good in special needs so I didn’t take my special needs bag. At 22 miles I was feeling them in my hamstrings and calves. I was just going to run up to the top of Mark and Dave hill. I figured the uphill running would help. Got to the top and had a stop and stretch. I had a six-minute lead and heard that Pete had walked through a few aid stations, so I thought I would be OK. If Paula can stop along Alii drive, though, anyone can.” From this article on

We have pulled together some questions from all the correspondence sent to us so that we can continue this conversation about race nutrition. What we would like to see is feedback and discussion on this topic. 98% of our readership are age groupers who are thirsty for the facts.

What if I am a faster athlete?

Wouldn’t nutrition strategies differ depending on the time you plan to be on course? We all know you need to have one & getting the balance right is important…. and effective hydration is critical. What you consume wouldn’t differ too much, but the rate and amount would differ markedly between an athlete competing for 8 hours and an athlete competing for 17 hours and everywhere in between.

The question needs to be asked to those who don’t consider themselves as ‘slower athletes’. Should you really ignore sodium?
Should slower athletes ignore sodium for that matter?

Do we need a published study on the benefits of sodium supplementation in respect to hydration? Isn’t it basic human physiology?

If you are admitted to hospital with dehydration, from fluid loss and an electrolyte imbalance, you are placed on a saline drip. A typical solution is a 1litre bag with 6200mg sodium chloride, 3200mg sodium caltrate, 420mg potassium chloride and 270mg calcium chloride. This type of solution is what every single hospital on the planet will use to assist in the recovery of dehydration.

Why do hospitals place such an emphasis on the importance of sodium replacement when treating dehydration?

Wouldn’t it then make sense to have some sodium in your drinks, in an attempt to minimise your losses, given the emphasis hospitals clearly place on its importance?


It is well documented that 75% of your nutrition during an Ironman is consumed on the bike. The less time you are on the bike, the less time you have to consume fluid and calories in preparation for the marathon. The faster you go, the higher the output. If the output is higher, naturally, energy expenditure and fluid loss will be greater.

For a lot of athletes competing in an Ironman it is unlikely that they will ever replace the amount of sweat loss occurring. As mentioned in the article the faster athletes typically lose more weight.

It makes sense when you compare the surface area of your skin (the largest organ of the body) to the size of your gut, it highlights the challenge you face getting even close to your sweat losses. Every single pore is flooding the skin for thermoregulation. The gut cannot keep up. It is simply a matter of volume.

We all know that sweating and the resulting evaporation of that sweat is the body’s natural cooling mechanism and defense for maintaining a safe core temperature. Given triathlon is predominantly a summer sport it is fair to say that most races are in warm to hot conditions. These types of environmental conditions naturally point toward a high level of sweat loss.

Don’t studies clearly show that as the percentage of fluid loss increases power output decreases?

Of the electrolytes we lose in sweat isn’t sodium the most abundant? If it isn’t why do hospitals replace so much of it when treating dehydration?

Isn’t sodium the only electrolyte that is extracellular (present in the bloodstream)?

Isn’t it sodium’s role to assist in the delivery of carbohydrate, oxygen and nutrients to the brain and active muscles?

As the sodium concentration in the bloodstream drops wouldn’t this effect the delivery of carbohydrate, oxygen and nutrients to the brain and active muscles?

Wouldn’t this effect how efficiently our muscles were receiving the very ingredients they require to function optimally?

Every body has a different sodium concentration in their sweat. It can range from around 800mg to 1800mg of sodium per litre of sweat. Some athletes have recorded as much as 2200mg per litre of sweat.

If you are caked in sodium during training and racing wouldn’t this mean you simply have a higher sodium concentration in your sweat?

Wouldn’t this be the reason why some athletes are more susceptible to cramping than others?

Wouldn’t the advice be to increase the amount of sodium in your fluid in an attempt to minimise the percentage of loss?

If you eat a lot of processed/refined foods and not do very much exercise it is fair to say that you are getting more than enough sodium in your diet.

What if I eat well and limit packaged foods? A healthy diet is generally quite low in sodium.

What about the accumulative loss of sodium from sweat due to my regular training efforts? Based on the sodium concentrations in sweat this would add up to a significant loss.

I have checked my sodium requirements per day for normal body function. For a healthy adult I need 2000mg per day. That adds up to 14,000mg per week. That doesn’t include what I need to replace due to sweat loss.

Am I really getting enough sodium in my diet?

Those athletes with a high sodium concentration in their sweat would find it very difficult to replace what they require. Wouldn’t they?

Hyponatremia is a medical condition also known as water intoxication. This medical condition occurs when sodium concentration in the blood gets too low.

Our body’s sophisticated; inbuilt mechanisms are mentioned in the article.

Why aren’t these sophisticated, inbuilt mechanisms warning us of hyponatremia and that our sodium levels have dropped so low that we may well die from it? Why are people still admitted to hospital suffering dehydration?

On the 2-part glucose 1-part fructose formula also mentioned in the article. There is some good research in regard to this. But aren’t these studies performed at low intensity? What percentage of athletes race at low intensity? What if I race at a solid or high intensity?

From a practical stand point. Energy gels are naturally sweet. Fructose is two and half times sweeter than glucose. Why would you add fructose to an energy gel and make it even sweeter. With the importance of carbohydrate intake during activity wouldn’t this sickly sweet formula discourage consumption during endurance events?

Surely a single source carbohydrate would work better at a solid to high intensity. Wouldn’t it?

Karl Hayes

Head of Rest and Recovery

Karl is a keen age group triathlete who races more than he trains. Good life balance! Karl works in the media industry in Australia and is passionate about the sport of triathlon.

  • Dr Nicole Anderson

    There are lots of questions and not nearly enough answers! Like yourself, I have realised there is probably no “one size fits all” formula for nutrition, hydration, whatever. I think the answer partly lies in our genetic individuality and how this determines our ability to metabolise what nutrition we actually manage to absorb in the first place. Approx 30% of people are intolerant of fructose, therefore this will propbably cause gut problems in a fair percentage of triathletes using fructose in any concentration or ratio with glucose. Salt is also individual, however I am highly skeptical of sweat sodium measurements as an indicator of sodium replacement requirements. Sodium is also very toxic to us – and our skin is also an excretory organ for this, especially when the renal excretion potential is compromised, such as the case when excercising with ADH release. Cramping and sodium concentration has not been convincingly proven (IMHO) as cramps occur regularly in people with normal serum sodium concentrations. Personally I have never cramped in a race, I have only used salts once (at husbands insistence) and ended up vomiting. We dont design energy bars on our poo do we? Therefore I think simiply measuring what comes out is actually a bit simplistic (but oh so easily marketable!) So I think when it comes to nutrition, individuality is the most important concept and sage advice from experienced sports dieticians along this line would be the safest and most effective way to determine a nutrition strategy, rather than blind reliance on product marketing by the pros.

  • Dr Nicole Anderson

    Actually woops! I have cramped in a race – in the swim at the Melbourne IM this year I had horrific back and shoulder cramps unlike anything ever experienced swimming before – and I was hypothermic. Cramps are very common in the cold. These settled well on the bike after I ingested 300mg of magnesium, and despite being in aero most of the time which was probably the worst “position” to ease or stretch these muscles!. Magnesium is controversial, because it is not excreted in the sweat so much or in the urine and therefore not really on the radar for sports drinks etc. However, again, I think its individual and I would not recommend it to anyone unless they had already been found to be magnesium deficient. Also, in the medical tent at Hawaii – we used IV magnesium quite a lot – for cramps and hyponatraemia as well (in addition to hypertonic saline for the hyponatraemia). I think there is something in this that we are missing in regards to magnesium.

  • Regarding the sodium debate; as a company we have been conducting sweat testing on athletes for several years and have observed a difference of between 200mg – 1700mg in terms of sweat sodium levels between individuals.

    In our data there is a positive correlation between athletes who report they get cramp regularly, and them having higher sweat sodium levels. Whilst it is not a 100% consistent relationship, there does appear to be a link.

    Whilst published scientific evidence is somewhat thin on the ground for sodium benefitting performance we are gathering a lot of anecdotal reports of people for whom it does seem very beneficial, especially during longer and hotter events. We suspect the reason for this has to do with variations in individuals sweat sodium losses and their ability to tolerate different levels of loss before performance starts to suffer.

    In essence we believe that due to a variety of factors that vary from individual to individual (including training status, intensity and length of race, sweat sodium level, amount and type of fluid replacement and pre-race hydration strategy) that sodium supplementation is helpful to some athletes but not necessarily all.

    More info on the topic is available on our website

  • Dan Plews

    This was a great original article by Paul, and for me, one that the Tri-world has needed to hear for some time. It’s also great to see how it’s opened up a lot of questions, many of which remain unanswered. When we’ve all heard one side of the argument (the sports drink industry side) for so long, I guess it’s really hard to change our thinking. I’m sure Christopher Columbus had the same problem when he tried to convince everyone the world is round.
    I’m an ok triathlete myself (PB 70.3 of 4:08:00) and Performance Physiologist for the New Zealand Rowing Team, so I’m dealing with the pointy end of human performance all the time. Paul’s original article wasn’t saying that “hydration isn’t important”; it was merely stating that to get the BEST out of your performance and to meet your hydration requirements, simply ‘drink to thirst’. If we talk about personal hydration strategies; you’re inbuilt mechanism for thirst is exactly that. A recent meta-analysis by Goulet (2012) has laid this debate to rest for me when his findings supported his conclusion “that relying on thirst sensation to gauge the need for fluid replacement maximises cycling TT performance”.
    Regarding the role of sodium in cramping, you have to know that correlation does not imply causation. Yes high sweat sodium losses and cramping tend to occur at the same time, but the two events are unlikely linked. There is no mechanistic explanation even why a lack of sodium would cause a muscle to cramp or spasm. Indeed, the athletes who lose the MOST sweat during races (usually the greatest sweaters) have the HIGHEST post-race sodium concentrations (see Noakes 2010; British Journal of Sport Medicine). Its often forgetten that those who are the saltiest sweaters are in fact the ones that likely have the most salt in their diet, and their body is merely removing excess sodium through the skin (an excretory organ). Cramping occurs during prolonged exercise simply due to fatigue, I.e. going harder/longer than you’re used to. This is pretty much the situation for any of us in a race. If you look at Crowie’s bike splits over the past four years at Kona (2008: 4:37:19; 2009: 4:37.33; 2010: 4:39.35 and 2011: 4:24:05), you can see how he was much quicker in 2011. More speed typically requires more power. Thus, a more logical explanation for Crowie’s cramping was perhaps his extra effort from the bike section and subsequent fatigue; not because he ran out of salt tabs. It appears everyone is human… I certainly enjoy a bit of sodium in my sports drinks and gels when I train and race, but only because it makes them more palatable. The best way to avoid cramping is to simply train/prepare optimally and pace appropriately.