Everyday I cycle or swim and see people with just water in their bottles. Most athletes run on just water so what’s the difference? What should we be doing? This can be a confusing subject because 1 minute the doctor says reduce your salt to get lower blood pressure then the next minute you have the coach saying increase your salt to stop cramps and retain fluids during exercise?? Sounds like a big contradiction doesn’t it!!

Here’s my 2 cents on the subject.

Firstly lets disregard weekend warriors or exercise up to an hour, its well documented that the average person gets enough salt in their diet and this is what most doctors are referring too.


In summary of the below information here is the easiest way I can explain it.

  • If you just drink water eventually you will deplete your natural salts in your body
  • If you deplete these salts then you end up with hyponatremia symptoms read below and losing performance
  • Salts also facilitates carbohydrate absorption so if you don’t have any then your fuel source of carbs will not work


Further to the above there are so many races around the country where I cannot count the number of times I see people walking due to cramps or dizziness or just their performance levels have dropped .High Five now have more electrolytes at the correct level in all of their drink powders. More than just about anyone in the world but still holding the nice taste with large quantities of sodium, this is where many companies fail badly.

Furthermore some company’s try to get you to take large amounts of magnesium to overcome this cramping problem. However in reality the amount they put into a drink is so large that it just causes nausea and vomiting. This  is crazy because magnesium is really mainly a muscle relaxant, it’s not solving the problem as the problem lies in you sweating out your salts and depleting them.

The following products all have huge electrolyte replacements in and all can be used for training and racing 

Energy source
Energy source 4:1
Isotonic fluid replacement


A further explanation on the above in more detail as follows:-

Sweat contains 15 – 50 meq Na per liter (about 1 gram), and you can lose anywhere from 2 to 4 liters per hour while exercising. So in prolonged exercise, salt losses can be significant (up to 4 grams and beyond) the normal compensatory physiologic mechanisms available that is a huge amount to loose and in previous articles we have mentioned what happens to your performance if you’re dehydrated let alone your well being.


The next thing you might ask then is well why not just top up on water??

Well that makes the problem worse and over long distance events hyponatremia can set in. (Too much water flushes out your salts causing all types of problems.) Read on!

The magnitude of the problem of hyponatremia was emphasized by a study of the 64 finishers of the 1984 Hawaiian Ironman triathlon which demonstrated an abnormally low serum sodium concentration in 29%. As overhydration or “water intoxication” with a low blood sodium concentration can be accompanied by nausea, fatigue, confusion, and even seizures, it was in fact more of a risk to poor performance than dehydration.

In high-heat and humidity conditions, sodium depletion can occur in just a couple of hours. Beginners especially, who spend longer than average on the course, need to be particularly sensitive to this condition and especially if they overdrink salt-poor fluids – which describes many sports drinks.

There are several possible mechanisms for hyponatremia with prolonged exercise.

  • Sodium losses in sweat are moderate but total body sodium content is near normal and replacement of fluid losses with a LARGE volume of sodium free water dilutes out the blood sodium concentration. (The most likely.) 
  • Both sweat volume (water) and sweat sodium losses are large and the sodium losses are not adequately replaced by electrolytes in snacks or commercial drinks. Again, any water ingested dilutes out the blood sodium concentration – but in this scenario total body sodium content is also diminished. (More common in undertrained individuals or those competing in unusually hot and humid conditions.) 
  • An inappropriate release of the hormone vasopressin with exercise leads to a decreased urine volume but, unaware of this, the athlete continues water replacement at normal rates. Total body sodium concentration is normal, total body water content is above normal or baseline. (Felt to be uncommon alone, but may play some role in combination with either of the above two scenarios.)

What about salt (sodium chloride) replacement? It goes without saying that some sodium chloride is needed to replace sweat losses. But probably not much unless one is consciously avoiding salt in snacks and fluids (and of course any deficit will be accentuated in longer events). Many athletes, observing general healthy-diet guidelines, watch their sodium intake and keep it low. This is not necessarily a good strategy for most endurance athletes, especially if the event will be in high temperature/humidity conditions. Sodium chloride also facilitates carbohydrate absorption (optimal concentrations have not been defined) from liquid carbohydrate drinks

For aerobic-endurance athletes (especially those exercising under high heat and humidity conditions), it is reasonable to plan on an intake of up to a maximum of one gram (1,000 milligrams) of sodium per liter (quart) of fluid loss. This is about one-half teaspoon of salt. It is preferable to eat salty foods or drinks rather than ingest salt tablets. Studies have shown that salty foods and drinks appear to stimulate thirst, and thus prevent the unintentional intake of dangerously high amounts of sodium.

Sodium chloride also facilitates carbohydrate absorption.

The main reason electrolytes are added to sports drinks is that the glucose transporter is sodium dependent, ie. it needs sodium to work. Even if you don’t take sodium with the drink the intestine secretes sodium to do the job up to a certain level. The other reason is it maintains the sodium level in the body during very long periods of intense sweating, the blood osmolality stays high and this feeds back to the athlete drinking more and peeing less out.

The advantage of taking in carbohydrate is it generally lets you have a better quality/speedy workout so you adapt better and get faster. This applies in the off season as well, though not as much if you are going slower.