How we tested electrolyte drinks

As BikeRadar’s main fitness, health and nutrition writer, Jack Evans has tested energy drinks and gels, and participated in a ground-breaking sodium bicarbonate trial. 

Jack is also a keen amateur athlete, finishing in the top 100 of the UK national hill climb championship twice. Fuelling his own training has deepened his understanding of sports nutrition.

He’s supplemented his own experience by asking sports science experts what you need in an electrolyte drink. 

Since their key ingredient is sodium, Jack looked for drinks containing about 250mg of sodium per serving. He marked down brands that didn’t make this number clear on their packaging. 

Jack didn’t credit drinks for containing significant amounts of less important electrolytes, such as potassium and magnesium. Carbohydrates aren’t an important part of cycling electrolytes either. 

Next up was taste. This, of course, is personal. But Jack rated the product higher if he found them drinkable in warm conditions. After all, hydration is the primary function of an electrolyte drink. 

Jack also considered the value, by working out the price per serving. He marked up brands which test for banned substances and naturally flavour their electrolytes. 

Jack then tried each electrolyte drink on multiple rides of varying duration and intensity, and in the cold and heat. 

Our reviews are always editorially independent.

Buyer’s guide to cycling electrolytes

What are electrolytes and what do they do?

Electrolytes are charged ions carried in the bloodstream. They are responsible for vital bodily functions including maintenance of pH balance and nerve control.

As we sweat, we lose water and electrolytes – such as sodium, calcium, potassium and magnesium – from our blood plasma. 

Sodium is the most important electrolyte for cyclists because it can help you stay hydrated on a bike ride. 

“Sodium regulates our fluid balance, helps with fluid absorption and causes a sensation of thirst,” says Dr Nidia Rodriguez-Sanchez, who has a PhD in hydration physiology. 

Andy Blow, the CEO of Precision Fuel and Hydration, says: “The electrolyte you lose the most of by far is sodium.”

As a result, the best electrolyte drinks will principally contain sodium, usually in the form of sodium chloride. 

Do you need electrolytes? 

Hydration experts agree that replacing some sodium during exercise through electrolyte drinks is beneficial. 

Blow says: “When you’re riding for hours on end, particularly in the heat, electrolyte replacement becomes increasingly important.”

This is because your sodium intake needs to reflect your fluid intake, which should increase as you sweat. 

“If you don’t replace an adequate amount of sodium, you dilute your blood by dropping the sodium levels and not managing to keep up blood volume,” he adds. 

“So that’s the primary rationale for replacing sodium.”

Significant sodium loss can also cause hyponatremia, where the ratio of sodium to water in your blood drops excessively low. This can cause muscle damage, seizure or even coma. 

Some experts believe sodium depletion can increase your risk of cramping on a bike ride. Therefore, electrolyte drinks are recommended for people who cramp frequently. 

What is in an electrolyte drink?

Aside from sodium, the other electrolytes we sweat out are less important to replace, despite what some electrolyte drink makers claim. 

“Most drinks are really high in electrolytes like magnesium, which is not lost in sweat, or if it is, in really tiny amounts,” says Dr Tim Podlogar, from the University of Birmingham. 

“So the electrolyte composition is most of the time not ideal.”

Therefore, when looking for the best electrolyte drink for you, don’t prioritise high levels of potassium or magnesium. 

Although you will lose some of these minerals in sweat, Dr Rodriguez-Sanchez says: “We will replace them through our diet in the next meal.”

When should you drink electrolytes?

The best electrolyte drinks should help you stay hydrated on long, hot days, but you might not need any electrolytes on shorter rides in cool conditions. 

Blow says: “When you’re doing a couple of hours, your electrolyte requirements are not usually super high.

“You don’t lose enough within that period to cause you problems.”

Dr Podlogar agrees, adding: “For rides shorter than four hours, there is no evidence you need to supplement with additional electrolytes.”

But the nutritionist at Red Bull-Bora-Hansgrohe WorldTour team recommends drinking electrolytes while cycling in winter.

“In the winter, electrolytes are equally as important [as in summer],” he says. 

“Although sweat rates are low or non-existent, riders can experience the need to pee quite a lot in the first hour of a ride.”

Colder temperatures can cause blood vessels to constrict under the skin, prompting the body to remove water through urine. 

Dr Podlogar adds: “Electrolytes help you retain the fluid and so you have to pee less often.” 

How many electrolytes do you need?

While cycling, commercially available electrolyte powders and tablets are the most convenient way to replace electrolytes. 

They also contain different amounts of sodium, helping you find one that replaces the right amount of sodium for you. 

“As long as we are receiving around 110 milligrams per portion, that’s fine,” says Dr Rodriguez-Sanchez, a lecturer in physiology and nutrition at the University of Stirling. 

Standard-strength electrolyte drinks contain about 250mg of sodium per 500ml serving, so that’s more than enough for most people. 

Some of the best energy drinks also contain electrolytes. If you’re quite a light sweater or don’t ride much in the heat, these could work for you. 

Heavy sweaters might want a stronger dose of sodium though. 

“If we feel we’re losing a lot of sodium, then 500mg or a gram of sodium [per litre] is absolutely fine,” adds Dr Rodriguez-Sanchez. 

“Even if we are losing larger amounts of sodium, we don’t need to replace it all during the ride.”

In its range, Precision Fuel and Hydration makes some even stronger electrolytes: its PH 1500 contains 1,500mg of sodium per litre. 

These are worth experimenting with if your sodium loss rate is high, you’re planning on cycling in the heat for a long time and you’re cramp-prone. 

Sweat rates are highly individual and are influenced by factors such as gender and diet. A sweat test (costing about £120) will reveal how many electrolytes you lose in a litre of sweat. 

After sweating a lot, you should also increase your sodium intake through food.

Dr Rodriguez-Sanchez says: “The recommendation is to recover what was lost through sweating in the meal after the training or the competition by adding some soy sauce or salt to your food.”

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