Best energy drinks for cycling 2024: fuelling and hydration explained

A blend of carbohydrate, water and electrolytes. Most commercially available sports drinks contain a mix of carbohydrates from different sources (eg. sucrose, glucose, fructose) at a concentration of around 6-8%. They typically come as a powder, to be mixed with water.

As the body’s primary source of fuel during prolonged and high-intensity exercise, depletion of muscle carbohydrates is one of the primary causes of fatigue, and can severely limit your ability to perform on longer rides.

Studies show that consumption of a carbohydrate drink during rides lasting over 60 minutes is an effective way to boost endurance. By providing the working muscles with additional fuel you can delay fatigue, with some research suggesting up to a 20% improvement in performance during exercise lasting 90 minutes or more.

Ingesting carbohydrates during exercise also has positive effects on the central nervous system, which can provide an additional mental ‘boost’.

During rides lasting over 60 minutes, consuming 30-60g of carbohydrate per hour will delay fatigue and help you sustain an optimum pace. One litre of an isotonic carbohydrate drink will provide around 60g of carbohydrate – so aim for around 250ml every 15-20 minutes.

Drinks containing a blend of carbohydrates have been shown to boost absorption and increase the amount of carbohydrate that gets to the working muscles (see 2:1 glucose:fructose).

Avoid concentrated drinks containing more than 6-8% carbohydrate (hypertonic), as these slow the rate at which fluid is absorbed, and can also cause gastrointestinal discomfort.

Carbohydrate drinks are a convenient option, which have the added bonus of facilitating the replacement of fluid and electrolytes.

However, this isn’t to say it’s not possible to fuel your rides with real food – in a 2012 study from Appalachian State University, bananas were shown to be as effective as a 6% carbohydrate drink in sustaining power output and performance in a group of male cyclists completing a 75km time trial.

Reliance on carb drinks can be an expensive habit. To get around this consider making a DIY isotonic drink by mixing 200ml ordinary squash with 800ml cold water and a pinch of salt.

Whether you use a carb drink is up to you – the key is to develop a plan which allows you to consume the recommended 30-60g of carbohydrate per hour.

Electrolyte drinks containing 6-8% carbohydrate are known as isotonic – they contain the same concentration of dissolved particles (salts and sugars) as body fluids, which promotes hydration.

An advanced range of sports drinks, powders, bars and gels containing a blend of carbohydrate in a 2:1 ratio of glucose to fructose with added electrolytes.

Consuming carbohydrate during endurance exercise delays fatigue and boosts performance, but the amount that can actually be delivered to the working muscles is limited by the rate at which it can be absorbed from your digestive tract.

Current recommendations to consume 30-60g of carbohydrate an hour during prolonged exercise are based on research showing that glucose absorption is capped at around one gram per minute (or 60g per hour), with studies showing that higher concentrations are simply not absorbed, and can result in stomach upset.

However, research focusing on the impact of combining different types of carbohydrate has shown that when glucose is consumed with fructose, carbohydrate absorption can exceed 1.5g per minute, increasing the rate of delivery to the muscles to up to 90g per hour. This is thanks to the fact that fructose is transported and absorbed via a different mechanism than glucose.

Put simply, by combining carbohydrates, you can overcome the 60g per hour saturation rule, which increases fuel availability. But does this translate to better performance? Research suggests yes – in a 2004 trial comparing glucose, glucose/fructose or control (water) beverages in trained cyclists; rates of carbohydrate oxidation were 36% higher with the glucose/fructose beverage versus the pure glucose drink.

In addition, researchers found that the glucose/fructose drink spared the body’s stored carbohydrate, improved water uptake from the gut and reduced the rate of perceived exertion. More recently, researchers at Birmingham University simulating a one-hour time trial after two hours of riding found an 8% improvement in performance when using glucose/fructose beverage, compared to a glucose-only drink.

For rides lasting over an hour, try swapping your usual sports drink or energy gel for a 2:1 product to increase carbohydrate delivery from 60g to 90g per hour – this equates to 1,500ml of a drink, three gels or three bars.

Remember, any change in your fuelling strategy should be tried and tested, so don’t make the switch on the day of a competition – work towards titrating your usage upwards from the standard 60g per hour.

Bear in mind that to achieve the stated 90g an hour, you'd need to get through two servings - so either a concentrated mix, or two bottles an hour.

Multiple transportable carbohydrates have definite benefits which could translate into that all-important performance edge during an event. The advantage of 2:1 products is convenience and the precise ratio of glucose to fructose for maximum absorption.

Carbohydrate foods do contain a mix of sugars (bananas provide glucose and fructose in a 1:1 ratio), so you could experiment with different sources, although getting 90g of carb in the all-important 2:1 ratio will require some maths.

Hydration drinks are a mix of water and electrolytes (such as sodium and potassium) with little or no added carbohydrate, designed to replace the fluid and salts lost during exercise.

As core temperature rises during exercise the body compensates by sweating, creating a loss of water and electrolytes, with additional water lost via respiration. Although the body can cope with small changes in fluid volume, large sweat losses can lead to dehydration, which results in impaired performance, increased heart rate, reduced heat tolerance and lower reaction times.

The loss of electrolytes in sweat (primarily sodium) is also exacerbated during prolonged exercise or in hot weather. Failure to replace electrolytes, or dilution through excessive intake of plain water can result in hyponatremia (low levels of sodium) leading to muscle cramps, lethargy, nausea, headaches and in severe cases, death.

Hydration drinks prevent dehydration by replacing fluids and electrolytes. The addition of sodium also facilitates hydration as it stimulates thirst and also water absorption from the intestine, promoting fluid retention. Due to the dilution of electrolytes, plain water may also suppress thirst, while hydration drinks maintain a desire to drink.

Generally speaking, a specific hydration product isn’t necessary if you’re riding for under an hour, but it can be useful in maintaining hydration in hot conditions, or if sweat loss is high.

If you do choose one, the rule of thumb is to start your ride well-hydrated, and to adopt a regular pattern of drink intake, aiming for 125ml every 15 minutes. This will help to maintain fluid balance.

Remember that if you’re riding for over an hour, you’ll also need to take carbohydrates on board, as hydration drinks don’t contain enough carbohydrates to boost endurance.

Flavoured beverages increase your desire to drink, and fluid consumption is more closely matched to sweat loss when athletes are offered a flavoured drink over plain water during exercise. In hot and humid conditions they’re an effective way to maintain adequate hydration, although during longer rides you’ll need to consider a carbohydrate source.

On the downside, these drinks can be expensive, and in rides lasting under an hour in relatively cool conditions, good old water will do the job nicely. If you’re not a fan of plain water, you can add a bit of squash and a pinch of salt to your water bottle to increase motivation to drink.