Sports drinks combine water, carbohydrates, and electrolytes to help replace fluids and minerals lost during exercise and, when necessary, provide energy.
However, not every workout requires a sports drink. Its composition and the amount you need will depend on factors such as the duration and intensity of exercise, temperature, your sweat rate, and your carbohydrate requirements.
In this article, we explain what a sports drink should contain, when it can be useful, and how to prepare your own drink with carbohydrates and electrolytes.
When do we lose fluids?
Exposure to heat and engaging in exercise or sport, whether competitive or recreational, can significantly increase fluid loss through sweat.
Other conditions, such as cold temperatures or altitude, can also increase body water loss through breathing and urine.
When do you need a sports drink?
Not every workout requires a drink containing carbohydrates and electrolytes.
For short or low-intensity activities, particularly when performed under moderate environmental conditions, water may be sufficient to maintain adequate hydration.
Sports drinks become more useful as exercise duration or intensity increases, when sweat losses are high, or when training in hot conditions.
As a general reference for carbohydrate intake during exercise:
| Exercise duration | Suggested carbohydrate intake |
|---|---|
| <60 minutes | Carbohydrate intake during exercise is generally not necessary. |
| 1-2.5 hours | 30-60 g/h |
| >2.5 hours | Up to 90 g/h using combinations of different carbohydrate sources. |
These amounts should be adapted according to the type of sport, intensity, the athlete’s goals, and gastrointestinal tolerance.
Importance of replacing fluids during exercise
Replacing fluids during exercise helps to minimise the body water deficit caused by sweating.
Sports drinks may contain carbohydrates, electrolytes, and other ingredients that, in addition to supporting hydration, can provide energy during exercise.
The optimal composition will depend on factors such as:
- Duration and intensity of exercise.
- Amount of sweat produced.
- Environmental conditions.
- Carbohydrate requirements.
- Individual gastrointestinal tolerance.
How does dehydration affect performance?
Water loss during exercise can lead to hypohydration, meaning a body water deficit compared with an adequately hydrated state.
In sport, particular attention has been paid to losses of around 2% or more of body mass, as dehydration of this magnitude may compromise cardiovascular function and thermoregulation, particularly during prolonged exercise and in hot environments.
For example, a loss equivalent to 2% of body mass represents approximately:
- 1.2 kg in a 60 kg person.
- 1.4 kg in a 70 kg person.
- 1.6 kg in an 80 kg person.
For this reason, during prolonged exercise it is important to have a hydration strategy adapted to individual fluid losses.
What should a sports drink contain?
A sports drink can combine different components depending on its intended purpose.
Water
It is the main component of the drink and is responsible for replacing part of the fluid lost through sweat.
It also acts as a vehicle for the other ingredients and plays a role in regulating body temperature.
Carbohydrates
Carbohydrates can provide energy during exercise and help maintain high carbohydrate oxidation rates during prolonged exercise.
The type and amount of carbohydrates used also influence the concentration, sweetness, and characteristics of the drink.
According to Regulation (EU) No 432/2012, carbohydrate-electrolyte solutions contribute to the enhancement of water absorption during physical exercise and to the maintenance of endurance performance during prolonged endurance exercise, provided that the product meets the authorised conditions of use.
Sodium and other electrolytes
Sodium is the main electrolyte lost through sweat, making it particularly important during prolonged activities or when sweat losses are high.
- Sodium helps promote retention of ingested fluid and may improve the palatability of the drink.
- Potassium contributes to the normal functioning of the nervous system and muscles.
- Magnesium contributes to electrolyte balance.
- Chloride is another electrolyte present in sweat.
Why is the flavour of a sports drink important?
A key factor determining how much fluid we drink is palatability.
The flavour, texture, and temperature of the drink can influence drinking behaviour. Other factors, such as thirst, personal preferences, and previous experience with a particular drink, also play a role.
Therefore, in addition to formulating a sports drink correctly, it is important that it is pleasant and easy to consume during exercise.

Glucose and fructose: why combine different carbohydrates?
When we need high amounts of carbohydrates during exercise, it is not only important how much we consume, but also which sources we use.
Glucose from sources such as maltodextrin is primarily absorbed via the intestinal transporter SGLT1. When glucose intake is high, this pathway can become a limiting factor.
Fructose mainly uses another transporter, GLUT5.
For this reason, combining glucose and fructose sources allows different intestinal absorption pathways to be used, increasing the availability of carbohydrates consumed during prolonged exercise.
2:1 and 1:0.8 glucose-to-fructose ratios
Two of the most commonly used ratios for combining maltodextrin or glucose with fructose are:
- 2:1 ratio: the classic combination of approximately two parts maltodextrin or glucose to one part fructose, widely used when aiming for high carbohydrate intakes.
- 1:0.8 ratio: proportionally increases the amount of fructose compared with the 2:1 ratio and may be useful when consuming high amounts of carbohydrates.
There is no single ratio that is suitable for every athlete. Total carbohydrate intake, exercise duration and, especially, gastrointestinal tolerance should be taken into account.
The greater the amount of carbohydrates you want to consume during exercise, the more important it is to train your digestive tolerance beforehand.
How to make a homemade sports drink
You can prepare your own drink by combining three main components: water, carbohydrates, and mineral salts.
To provide carbohydrates, we can combine maltodextrin and fructose, while Evolytes can be used to add different mineral salts.
Recipe per 500 ml bottle:
| 2:1 ratio | 1:0.8 ratio | |
|---|---|---|
| Water | 500 ml | 500 ml |
| Maltodextrin | 30 g | 25 g |
| Fructose | 15 g | 20 g |
| Evolytes Powder | 2.5 g | 2.5 g |
| Carbohydrates | 45 g | 45 g |
How much should you drink to meet your carbohydrate requirements?
Each bottle in the recipe provides 45 g of carbohydrates. Therefore:
| Amount | Fluid | Carbohydrates |
|---|---|---|
| 1 bottle/h | 500 ml/h | 45 g/h |
| 1.5 bottles/h | 750 ml/h | 67.5 g/h |
| 2 bottles/h | 1000 ml/h | 90 g/h |
However, fluid and carbohydrate requirements should be individualised separately.
There is no need to increase fluid intake solely to reach a specific amount of carbohydrates per hour. If you need more carbohydrates but less fluid, you can supplement your strategy with other carbohydrate sources.
Preparation
- Pour around 300 ml of cold water into the bottle.
- Add the maltodextrin, fructose, and serving of Evolytes.
- Shake until all the ingredients are completely dissolved.
- Top up with water until you reach 500 ml.
- Keep the drink cool during training whenever possible.
How to calculate your sweat rate
Fluid requirements can vary considerably between athletes.
A simple way to estimate them is to weigh yourself before and after a training session and record how much fluid you have consumed.
You can use the following formula:
Sweat rate (L/h) ≈ [pre-exercise weight − post-exercise weight + fluid consumed − urine produced] / exercise duration in hours
For example:
- Pre-exercise weight: 70 kg.
- Post-exercise weight: 69.4 kg.
- Fluid consumed: 500 ml.
- Duration: 1 hour.
- No urine produced during the training session.
The estimated loss would be approximately 1.1 litres of sweat per hour.
This calculation provides a useful reference for individualising your strategy, although it does not necessarily mean that you should replace 100% of the fluid lost during exercise.
Tips to improve tolerance to your sports drink
- Do not try your strategy for the first time in competition. Test the amounts of fluid, carbohydrates, and electrolytes during training beforehand.
- Increase carbohydrates gradually. If you want to reach high intakes, gradually train your digestive system to tolerate them.
- Adjust the concentration. If the drink is too concentrated or causes digestive discomfort, use more water or reduce the amount of carbohydrates.
- Consider flavour and temperature. A pleasant, cool drink may make it easier to consume during exercise.
- Individualise your strategy. Temperature, humidity, intensity, duration, and sweat rate all affect your requirements.
Is a sports drink the same as an energy drink?
No. Although their names can sometimes cause confusion, they serve different purposes.
- A sports drink is primarily formulated to provide fluid and, depending on its composition, carbohydrates and electrolytes during exercise.
- An energy drink, on the other hand, usually contains caffeine and other ingredients and is not necessarily formulated to meet hydration requirements during exercise.
Conclusion
A good sports hydration strategy goes beyond simply drinking water.
During prolonged exercise, combining water, carbohydrates, and electrolytes can help meet part of your fluid, energy, and mineral requirements at the same time.
The appropriate amount will depend on the duration and intensity of exercise, environmental conditions, your sweat rate, and your carbohydrate requirements.
If you prepare your own drink, you can adjust both its concentration and the ratio of maltodextrin to fructose according to your goals.
Above all, test and train your hydration and nutrition strategy before using it in competition.
References
- Almond CS, Shin AY, Fortescue EB, et al. Hyponatremia among runners in the Boston Marathon. N Engl J Med. 2005;352:1550-1556.
- Armstrong LE. Assessing hydration status: The elusive gold standard. J Am Coll Nutr. 2007;26:575S-584S.
- Baker LB, Dougherty KA, Chow M, Kenney WL. Progressive dehydration causes a progressive decline in basketball skill performance. Med Sci Sports Exerc. 2007;39:1114-1123.
- Below PR, Mora-Rodriguez R, Gonzalez-Alonso J, Coyle EF. Fluid and carbohydrate ingestion independently improve performance during 1 h of intense exercise. Med Sci Sports Exerc. 1995;27:200-210.
- Burke LM, Wood C, Pyne DB, Telford DR, Saunders PU. Effect of carbohydrate intake on half-marathon performance of well-trained runners. Int J Sport Nutr Exerc Metab. 2005;15:573-589.
- Cermak NM, van Loon LJC. The use of carbohydrates during exercise as an ergogenic aid. Sports Med. 2013.
Related Posts
- Post-Workout Carbohydrates
- How Does Carbohydrate Intake Before, During or After Exercise Affect Performance?
- Fluid Retention
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