Sports drinks and performance

For optimal performance, athletes should be hydrated and adequately fuelled during exercise. Although there are a wide range of beverages marketed with reference to sport or performance;  sports drinks are specifically designed to provide the right balance of carbohydrate, electrolytes and fluid to adequately fuel exercise and provide fluid for hydration. When used appropriately they can result in performance benefits.

Table 1 below compares the nutritional composition of commercially available sports drinks available in Australia. If drinking sports drink products in powdered form it is important to follow the manufacturer’s instructions to ensure that the carbohydrate and electrolyte balance is optimal for gut absorption, fluid balance and fuel delivery. Incorrect preparation may lead to gastrointestinal discomfort and a negative impact on performance.

PER 100ML

n/a = no value given

PER 1 Litre

n/a = no value given

What’s in a sports drink?

Carbohydrate

Carbohydrate can have performance benefits in a range of sporting events by providing a fuel source for muscles and the brain. Carbohydrate also contributes to the palatability (taste) of sports drinks. Most sports drinks contain 6- 8% carbohydrate (6-8g/L). Carbohydrate concentrations above this can impair gastric emptying and lead to gut upset during exercise and impair performance.

Electrolytes

Sports drinks include the electrolytes sodium and potassium. The sodium content of sports drinks encourages fluid intake by driving the thirst mechanism, while also increasing absorption and fluid retention. Sports drinks may also help with salt replacement for athletes who are heavy or salty sweaters. Low sodium drinks may not be suitable when speedy rehydration is necessary (i.e. when there is a need replace a fluid deficit in a short period of time). The addition of potassium to sports drinks helps maintain electrolyte balance and can assist with muscle contraction during exercise.

Flavour

Flavour is an important feature of sports drinks that helps to increase voluntary fluid intake (compared to water) during or after exercise.

Other Ingredients

Some beverages marketed as sports drinks have other added ingredients like vitamins, minerals, protein and herbal ingredients. These extra ingredients are likely to offer very little (if any) additional benefit over standard sports drink and may affect the palatability, and subsequently consumption of the fluid. Some sports drinks also contain caffeine which can have performance benefits. For more information see the Caffeine factsheet.

Practical applications

1. Before exercise

Sports drinks may be useful before an event to fine tune fluid and fuel (carbohydrate) intake. The carbohydrate in sports drinks can increase carbohydrate availability, while the added sodium may reduce urine losses before exercise begins.

2. During exercise

Sports drinks are primarily designed for use during exercise lasting more than 90 minutes by providing optimal fluid and fuel delivery. Sports drinks may allow athletes to perform for longer and more effectively in training and competition by providing energy to working muscles and the brain.

3. Recovery

Sports drinks can help meet nutrition recovery goals by replacing fluids and electrolytes lost in sweat and helping to replenish glycogen stores. If there is limited time between training sessions or competition, drinks with higher sodium content may promote more effective rehydration. To meet all recovery goals, the ingestion of sports drinks should be complimented with foods and fluids that provide adequate carbohydrate, protein, and other nutrients essential for recovery.

Potential side effects

Gastrointestinal upset

Excessive consumption of sports drink can cause gastrointestinal upset. It is recommended that athletes drink small amounts frequently (rather than a lot at once) and trial options during training.

Dental health

Acidic foods and fluids are one of the factors linked to tooth enamel erosion. Sports drinks, together with fruit juice, soft drink, wine, beer, tea and coffee are all examples of acidic fluids. The use of sports drinks alone is unlikely to cause dental erosion. However, athletes who use large quantities of sports drinks for prolonged periods should pay extra attention to dental hygiene. For more information see the Dental Health for Athletes factsheet.

Summary

The ideal sports drink depends on personal taste preferences and individual tolerance. While the exact nutrition composition of sports drinks varies, they generally contain similar amounts of carbohydrate and electrolytes. Sports drinks should be trialled during training rather than in competition. Accredited Sports Dietitian can help you develop an individual fluid plan including sports drinks that is appropriate for you. To find one near you, click here.