Isotonic, the best sports drink for athletes

Dec 18, 2018 7:51:28 PM
5 min read

What is the perfect sports drink for triathletes?

One of the questions we get most often, is what you should be drinking as a triathlete, and what the best sports drink is for hydration and energy.

To answer that question, let's look at what the perfect sports drink needs to do.

The benefits of the perfect sports drink

Ideally, your perfect sports drink should tick all these boxes:

  • Hydration
  • Energy
  • Easy to digest
  • Not bad for the teeth

The Isotonic by Hiddit ticks all these boxes. Let's find out why!


Probably the most important function of any sports drink, is to ensure fast hydration. It is impossible to perform at your best level without paying attention to hydration, as dehydration is disastrous for your performance.

As you dehydrate, your blood becomes ticker and your heart has to pump harder to make it circulate through your body. This can lead to an increased heart rate of 3.29 beats per minute, per percent of dehydration (see study).

For example, if a 65 kilogram triathlete dehydrates by 3% (almost 2 liters), his/her heart rate will increase by 10 beats per minute! Of course, this will hugely impact performance and comfort.

Dehydration will also cause your body to heat up and increase your core temperature, putting you at a greater risk of heat stroke.

In fact, there is so much research done on hydration, that we can state, without a shadow of a doubt, that dehydration of more than 2% will always negatively impact performance - and even lead to death in the more extreme circumstances.

That is why we always advocate athletes to keep track of their hydration levels and implement a strategy including their personal sweat ratio. You can read more about this in our free eBook on racing nutrition.

As one can assume, a sports drink will always contain water, but that alone is not enough. To optimize hydration, we need to look at a few extra ingredients:

  • Sodium and other electrolytes
  • Glucose

Water balance in your body is maintained by substances called electrolytes, such as sodium, magnesium, calcium, potassium and chloride.

As you sweat, you lose these minerals and they will need to be replenished. In HIDDIT's Isotonic, you will find all these electrolytes in the exact ratio found in sweat.

It would take us too far to look at each electrolyte separately, but sodium deserves our attention as it is the most important one for hydration.

In fact, water transits from the intestine into the bloodstream only in the presence of sodium (salt). And not only water is dependent on sodium for absorption, so is glucose. 

This is extremely important for endurance athletes: without sufficient sodium, you do not absorb water and glucose, the two most important factors for optimal performance.

sodium glucose

Things get even more interesting: sodium and glucose combine to pass the intestinal wall, but at that exact same time, they take 210 molecules of water with them, in a process called facilitated transport. By adding sodium and glucose to water, the water will be absorbed faster, decreasing the risk of dehydration.

But at what ratio do we need to add glucose and sodium? Ideally, at an "isotonic" level, meaning the number of particles in the sports drink is similar to the level of particles in the blood.

This triggers osmosis, also called passive transport: the easy transfer of fluid and nutrients through the membranes.

To summarize: adding key electrolytes and glucose to water improves hydration.

A properly formulated sports drink containing sodium also decreases the risk of hyponatremia, a condition of insufficient sodium levels in the body, caused mainly by drinking too much water (containing no sodium).

This has even caused several deaths among athletes, as you can read here.


Especially if you do long training sessions or races, you risk depleting glycogen, the stored glucose in your body.

Glucose is your body's preferred fuel for higher-intensity endurance efforts such as triathlon.

It is important to provide your body with the energy it needs to compete at its best level. Therefore, it is logical that your sports drink also provides energy.

Even during short, intense efforts, it is proven sports drinks will boost performance, as demonstrated in this study by professor Asker Jeukendrup.

However, you cannot consume infinite levels of carbohydrates during training: your intestines are not able to digest excessive amounts, especially not when your muscles require a lot of blood to perform.

Up to quite recently, the general advice was to not exceed 60 grams of carbohydrates per hour. However, recent studies have proven that this can be increased to 90 grams by distributing the total amount of carbohydrates between glucose and fructose in a 2:1 ratio.

Applying this principle, as we do in our Isotonic, enables you to increase carbohydrate intake (positively influencing performance) and improve digestion.

Many triathletes get intestinal cramping and diarrhea during races and training, because the carbohydrates they consume during the effort remain undigested in their intestines. 

Using a properly formulated sports drink such as HIDDIT'S Isotonic will reduce this risk!

You might also notice that we use 4 different sources of carbohydrates in our formula. Different sources have different digestion rates, ensuring you have a fast but steady supply of energy during training or racing.

Easy to digest

The last thing you want during a race, is gastro-intestinal issues such as stomach pain, cramps or diarrhea. As you've seen, one of the solutions is the use of different sources of carbohydrates to optimize digestion.

But we take some extra steps:

  • Only natural flavors
  • No artificial sweeteners: sucralose and other artificial sweeteners can negatively impact the gut.
  • No colorings: if it doesn't have a function, you don't need it in your drink. A bright red color will not make you faster.
  • Low acidity: all our Isotonics have a pH between 5 and 7, making them very easy on the stomach.

By keeping our Isotonic sports drinks as clean as possible, we minimize the risk of any stomach or intestinal upset.

Not bad for your teeth

Maybe not the first thing you think about when considering a sports drink, but with training volumes easily reaching 10-20 hours per week, chances are high you will be consuming a lot of fluids!

Did you know that triathletes are at a greater risk of tooth decay than the general population? One of the reasons is 'heavy mouth breathing': the high breathing rate leaves the mouth dry, making it easier for bacteria to thrive and cause health issues, as shown in this study in the Scandinavian Journal of Sports.

It is not surprising that a study by the British Journal of sports found that of the 300+ athletes participating in the 2012 Olympics, the majority had poor oral health.

Besides the obvious visual and aesthetic effect, poor oral health negatively impacts general health and performance.

One of the culprits for tooth decay is the use of sports drinks, combining a low pH (high acidity) with sugar. This has been shown to damage tooth enamel.

So how can you look after your teeth while still properly fueling and  hydrating? The solution was found in this study by Asker Jeukendrup: the combination of a high pH (low acidity meaning a pH over 3.8) and calcium at a very specific concentration (355 mg/l) results in ZERO tooth enamel decay. In fact, consuming this specially formulated drink had an indistinguishable effect on teeth as plain water.

That is why you will find calcium in our Isotonic at exactly that concentration, combined with a pH higher than 5. Easy on the stomach and easy on the teeth!

Our new Neutral Taste Isotonic is the best for people with sensitive stomachs: it boasts a pH of 7, the same as plain water!

You can find the pH readings of many commercially available sports drinks in this study.


In the search for the perfect sports drink for athletes, it is important to look at several factors. At HIDDIT, we believe we have covered all bases to produce an extremely high quality isotonic sports drink that is an excellent choice for triathletes of all levels, based on the latest research and real-life input.

Want to give it a try? Visit our shop now!

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