Best sports drink for endurance: what UK athletes should choose

You are heading out to train and reach for a bottle. Should it contain electrolytes only, or carbohydrates as well? The labels rarely make the decision easier. “Hydration”, “sports drink” and “isotonic” are often treated as interchangeable terms, even though the drinks may serve different jobs.

The useful question is not which type of drink is universally better. It is: do you need fluid and electrolytes, carbohydrate fuel, or both for this session?

For a short, easy session, water may be enough; electrolytes become more relevant when it is hot or you expect meaningful sweat loss. As duration and intensity rise, carbohydrate becomes increasingly useful because working muscle draws on stored glycogen and blood glucose. Sweat rate creates a separate demand, which is why a hot 45-minute run and a cool four-hour ride require different plans.

The right choice therefore depends on three variables: session duration, intensity and your individual sweat rate. Once those are clear, the shelf becomes much less confusing.

what is an electrolyte drink?

An electrolyte drink supplies minerals dissolved in fluid, usually with little or no carbohydrate. Sodium is the main electrolyte lost in sweat and is central to extracellular fluid balance. Potassium is the major intracellular cation, while magnesium and calcium are involved in normal muscle and nerve processes.

Electrolytes without carbohydrate can be a sensible choice when fuel demand is low but sweat loss is relevant. Examples include an easy session under 60 minutes in warm weather, a low-intensity recovery ride, or a short heat-acclimation session. In cool conditions, a well-fed athlete doing 30–45 easy minutes may need nothing more than water.

An electrolyte drink is not a watered-down sports drink. It solves a distinct problem: replacing fluid and selected minerals without automatically adding fuel. That can be useful when you have eaten recently, are keeping a session deliberately easy, or prefer to take carbohydrate separately from gels or food.

what is a sports drink?

In this guide, “sports drink” means a carbohydrate-electrolyte drink: fluid, electrolytes and a measurable amount of carbohydrate in the same bottle. Always check the nutrition panel, because the name alone does not guarantee a useful carbohydrate dose.

Carbohydrate may be supplied as glucose, maltodextrin or a glucose-fructose combination. Maltodextrin is a glucose polymer that can deliver carbohydrate with less sweetness than an equivalent amount of simple sugar. 

During moderate-to-high-intensity exercise, muscle glycogen and blood glucose contribute to energy production. Consuming carbohydrate during a longer session provides an external fuel source and can reduce reliance on the body’s finite carbohydrate stores. That does not mean every workout needs a sugary bottle.

For most athletes, carbohydrate (Heed) during exercise starts to become practically relevant as a session moves beyond roughly 60–75 minutes, especially when the work is steady or hard. It may be useful sooner during competition or demanding intervals, while an easy 75-minute session after a normal meal may require little or none. The threshold is a starting point, not a stopwatch alarm.

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the science: when do athletes need carbohydrates?

Muscle glycogen does not suddenly run out at 60 minutes. Glycogen use rises with exercise intensity, and the rate also varies with training status, pre-session nutrition and the athlete’s starting stores. A hard tempo run can create a greater carbohydrate demand than a longer easy spin. Training duration matters, but it never tells the whole story.

The familiar 60-minute rule comes from practical sports-nutrition guidance rather than a universal depletion time. The joint position statement from the American College of Sports Medicine, Academy of Nutrition and Dietetics, and Dietitians of Canada recommends matching carbohydrate intake to the demands of the event. A useful field framework is:

• Under about 45 minutes: carbohydrate during exercise is generally unnecessary for a well-fuelled athlete.
• Around 45–75 minutes at sustained high intensity: small amounts may be useful; a full hourly fuelling plan is not always required.
• About 1–2.5 hours: 30–60 g of carbohydrate per hour is an evidence-based range for most endurance athletes.

These figures are total intake from drinks, gels, chews and food combined. A bottle containing 30 g plus two gels containing 25 g each would provide 80 g, not 30 g. More fuel is not automatically better: exceeding what your gut can absorb can leave carbohydrate sitting in the intestine and increase gastrointestinal discomfort.

This is where gut training matters. Begin with a tolerable intake in ordinary training, calculate grams per hour, and gradually practise the amount and product combination intended for racing. Liquid carbohydrate suits athletes who struggle to chew or swallow at intensity. Others feel better keeping the bottle light and taking measured gels or solids. Do not introduce a 90 g-per-hour plan on race morning and hope enthusiasm will handle the plumbing.

Body size, pace and training status influence energy expenditure, but within-exercise targets are commonly expressed as absolute grams per hour because intestinal absorption capacity does not simply scale with body mass. A larger athlete does not automatically need double the carbohydrate of a smaller athlete.

Heat creates another layer. Hot or humid conditions can increase sweat rate and therefore fluid and sodium loss without changing a short session into a carbohydrate-demanding one. Conversely, a cool long ride may require substantial carbohydrate even when sweat loss is modest. Plan fuel and hydration together, but do not confuse them.

matching the drink to the session

Use the table as a starting framework, then adjust it with experience. “Light carbs” means a deliberately modest intake that fits the session; it is not a separate regulated product category.

Session type	Duration	Intensity	Recommended starting point
Easy recovery ride	Under 60 min	Low	Water; add electrolytes(Endurolytes) in heat or with meaningful sweat loss
Tempo run	60–90 min	Moderate–high	Electrolytes plus a light carbohydrate (Heed)intake
Long ride or sportive	2–5 hrs	Moderate–high	Sports drink and/or gels to reach a practised hourly carb target
Hot-weather training	Any	Any	Prioritise an individual fluid and electrolyte plan; add carbs according to duration and intensity
Race day	90 min+	High	Rehearsed carbohydrate and electrolyte strategy using total g per hour

For a tempo run lasting 75 minutes, a lightly mixed carbohydrate-electrolyte drink may provide enough fuel without requiring solids. For a four-hour sportive, one bottle of sports drink is unlikely to cover the whole carbohydrate requirement; gels, chews or suitable food may be added, with the total calculated in g per hour. Our Cycling Nutrition Hub and Triathlon Nutrition Hub provide sport-specific planning context.

Sweat rate can be estimated by comparing pre- and post-session body mass while accounting for fluid consumed and urine passed. Conditions matter, so a cool training result should not be copied blindly into a hot race. Avoid trying to replace every millilitre at all costs: excessive drinking can be dangerous. The British Journal of Sports Medicine consensus statement on exercise-associated hyponatraemia emphasises avoiding overdrinking; sodium intake does not make excessive fluid consumption safe.

Gut sensitivity also changes the choice. Some athletes tolerate carbohydrate better in liquid because it is delivered in small, regular sips. Others prefer to separate fuel from hydration so bottle strength stays consistent when weather and drinking volume change.

combining both strategies

Fuel and hydration do not have to come from the same product. A separated strategy might use an electrolyte drink or water in the bottles, with carbohydrate supplied through measured energy gels, chews or food. The athlete can then increase fluid intake in hotter conditions without accidentally increasing carbohydrate at the same rate.

Separation offers three practical advantages. First, dosing is clearer: you can count carbohydrate in g per hour while adjusting fluid according to thirst, conditions and a tested sweat plan. Second, it provides gut control because a bottle is less likely to become overly concentrated. Third, it gives flexibility at aid stations, where plain water may be easier to find than a familiar drink mix.

The trade-off is complexity. You must carry, open and remember separate products. On a shorter race, during travel, or in an event where handling gels is awkward, an all-in-one sports drink can be the simpler choice. A product such as HEED combines carbohydrate and electrolytes, but the serving size must still be checked against the athlete’s total hourly plan.

Neither method wins by default. The best setup is the one that provides the intended amounts, works in the expected weather and has already passed the training test.

common mistakes athletes make

1. using a full sports drink for every short session

A well-fed athlete doing an easy 45-minute run usually does not need carbohydrate during the workout. A sports drink is not automatically harmful, but it may add fuel that the session does not require. Water is often enough; consider electrolytes when heat or sweat loss makes them relevant.

2. taking electrolytes only on a four-hour ride

Electrolytes do not replace carbohydrate. An electrolyte-only bottle may support the hydration plan, but it cannot supply the 30–60 g per hour commonly used during endurance exercise. Calculate total carbohydrate across every bottle, gel and item of food before setting off.

3. ignoring sodium—or assuming more is always better

Sodium is normally the primary electrolyte considered in prolonged sweaty exercise because it is the main electrolyte lost in sweat. Losses vary widely, however, and visible salt marks are not a laboratory test. Use product labels, experience and, when warranted, professional sweat testing rather than copying another athlete’s dose. People with a medical condition or prescribed sodium restriction should obtain clinical advice.

4. treating “isotonic” as a fuelling plan

“Isotonic” describes the concentration of a solution relative to body fluids; it does not tell you how many grams of carbohydrate you will consume per hour. Read the nutrition panel, note the grams per serving, account for bottle size and add every other fuel source. The arithmetic is dull, but so is running out of fuel at kilometre 32.

5. testing the plan on race day

Flavour fatigue, sweetness, bottle concentration and gut tolerance all change over several hours. Rehearse the exact products, doses and timings in race-like training. The Race Nutrition Planner and Beginner’s Guide to Endurance Fuelling can help turn a target into a practical schedule.

choose for the session, not the label

Use water or an electrolyte drink when the main job is hydration and carbohydrate demand is low. Add carbohydrate as sessions become longer or harder, generally working within 30–60 g per hour for endurance exercise and considering up to 90 g per hour only for long events with a trained gut and an appropriate carbohydrate blend.

Heat, humidity and sweat rate can raise fluid and electrolyte needs independently of fuel needs. That is why the right choice is session-specific, not brand-specific. Calculate the dose, practise it in training and adjust from evidence rather than habit.

Ready to build the plan? Explore the Electrolytes Hub, compare a carbohydrate-electrolyte option such as HEED, browse energy gels, or start with the Cycling and Triathlon hubs.

frequently asked questions

what is the difference between a sports drink and an electrolyte drink?

An electrolyte drink mainly provides fluid and minerals, usually with little or no carbohydrate. A sports drink, as defined here, provides carbohydrate and electrolytes together. Check the nutrition panel because product names and “isotonic” wording do not confirm the carbohydrate dose.

do i need carbohydrates for exercise under 60 minutes?

Usually not during an easy or moderate session if you started well fed. Carbohydrate may still be useful for sustained high-intensity work, competition, or when the session begins with low glycogen availability. Water may be enough; use electrolytes according to conditions and sweat loss.

can i use an electrolyte drink instead of a sports drink on a long ride?

Yes, but only if carbohydrate comes from another source such as gels, chews or food. An electrolyte drink can cover part of the hydration strategy; it cannot replace a planned carbohydrate intake on a multi-hour ride.

how many grams of carbohydrate should i consume per hour during endurance exercise?

For exercise lasting about 1–2.5 hours, 30 g per hour is a common evidence-based range. For events beyond roughly 2.5–3 hours, trained athletes may use up to 30 -60 g per hour. Practise the target and count all sources.

why is sodium the most important electrolyte during exercise?

Sodium is often the primary electrolyte in an exercise hydration plan because it is the main electrolyte lost in sweat and plays a central role in extracellular fluid balance. It is not the only electrolyte the body needs, and the correct intake varies. Sodium also cannot compensate for drinking excessive fluid.

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