There are now a huge range of so-called ‘energy’ and ‘sports’ drinks on the market. They claim to wake you up, help you concentrate, improve performance (at both sport and life), and speed your recovery and rehydration after exercise. If you listened to the advertising, you might well conclude that these were wonder-drinks akin to so-called ‘superfoods’.

However, do these claims stack up when weighed against the science of what’s in the drinks? Or are these drinks much more like superfoods than we realised, and the hype significantly outweighs the reality? And perhaps more importantly, what is really in these drinks? This page explores the science, evidence and reality, and provides some advice for when these drinks might be useful, and when (and by whom) they should be avoided.

Sports vs. Energy Drinks

First of all, what’s the difference between energy drinks and sports drinks? The key is in the purpose and the ingredients.

• Energy drinks aim to provide a fast boost of energy

  Apart from water, the main ingredients in these drinks are therefore caffeine and sugar.

  Many of them also contain an extract from the guarana plant, which has a similar effect to caffeine. Some also have added taurine, an amino acid that is supposed to increase the effects of caffeine. Others may also contain vitamins.

  Energy drinks include Red Bull, Rockstar and Monster.

• Sports drinks are designed to help athletes to rehydrate after exercise.

  They therefore contain essential minerals that may be lost through sweating, such as potassium, calcium, sodium and magnesium. These are known as ‘electrolytes’, and help to keep the right balance of fluids in the body. Like energy drinks, many sports drinks also contain carbohydrate in the form of sugar, and sometimes some protein. They may be available in liquid or powdered form.

  Examples of sports drinks include Lucozade Sport and Gatorade.

  There is more about how minerals work in our page on Dietary Minerals.

The big question about both energy and sports drinks is when and how should they be used.

The answer is that almost nobody actually needs to use either, and that using either at the wrong time or in the wrong way can have negative effects.

Using Energy Drinks

The main effects of energy drinks come from the caffeine and sugar. These drinks therefore provide a rapid burst of energy—which is what their users want.

However, this is often rapidly followed by a ‘crash’ when the sugar is removed from the blood stream (there is more about this in our page on Complex Carbohydrates, Sugar and Diet). Caffeine and sugar also have other health effects, including:

• Increased blood pressure, coupled with the potential to cause cardiac arrythmias.

• Weight gain, thanks to the quantity of sugar in energy drinks.

• An inflammatory effect on the body because energy drinks contain few nutrients apart from sugar and caffeine, so there is nothing to ‘cushion’ the sugar spike.

• The potential for withdrawal symptoms, including headaches, feeling tired, and having trouble concentrating—all of which lead you to reach for another energy drink, only to repeat the cycle.

• Sleep problems because caffeine is a stimulant.

• Tooth decay because of the large amounts of sugar and acid in many energy drinks.

These problems are particularly extreme in young people, and there have been cases of illness or even death in young people who have consumed too many energy drinks.

This has led the American Academy of Pediatrics to advise that children and teenagers should not consume energy drinks.

Given that pregnant women are also advised to avoid drinking too much coffee because of the caffeine, it seems likely that they should also avoid energy drinks.

Energy drinks are also largely unregulated in many countries, including the US. It is therefore very hard to know exactly how much caffeine they contain, because some of the added ingredients may contain caffeine on top of the caffeine added directly. Additionally, little is known about the effects of some of these added ingredients. You therefore cannot be completely confident what you are actually consuming, or the effect that it will have.

The general consensus, therefore, is that energy drinks are probably reasonably safe for most adults to use—but only occasionally and in moderation. They may ward off tiredness at least for a period. However, prolonged use will not be healthy. The use of energy drinks is also unlikely to improve athletic performance except in highly trained athletes. The effect on performance is also similar for low and high doses of caffeine, so there is no need for the high dose in energy drinks.

Using Sports Drinks

Energy drinks are therefore likely to be totally unnecessary, and often actively bad for your health. What about sports drinks, though?

On paper, sports drinks seem relatively benign: a way to replace lost electrolytes and rehydrate quickly. There are three main types:

• Isotonic drinks contain similar concentrations of sugar and salt to the human body. These are the most widely available drinks, and are broadly designed to replace water, salt and sugars lost during exercise.

• Hypertonic drinks contain higher concentrations of sugar and salt than are normally found in the body. They are therefore designed to rapidly replace lost salt, and replenish glycogen stores after exercise, and are often used in conjunction with isotonic drinks.

• Hypotonic drinks are less concentrated than the human body, and are therefore mainly designed to replace fluids lost through exercise.

However, advice from most health bodies, health professionals and sports nutritionists is that the best way to rehydrate after exercise is to drink water.

There is also considerable criticism of the sports drinks industry about the claims made for their products. There have been plenty of studies, but most of them among highly trained athletes, usually young men. It is therefore very hard to generalise these findings to the population as a whole. Many of the findings are also inconclusive anyway.

The general consensus is therefore that sports drinks are largely unnecessary.

There is also some evidence that these drinks cause problems such as weight gain and tooth decay because of the sugar content and acidic nature of most sports drinks. Some people can also experience gastrointestinal discomfort after taking sports drinks (again, because of the carbohydrate content).

There are a few notable exceptions to the general rule, and they tend to involve higher intensity or longer duration exercise sessions.

For example, endurance athletes taking part in a long-distance event in the heat (where they are likely to sweat a lot) may benefit from a drink containing electrolytes. Some nutritionists also suggest that the sweetness and flavour of sports drinks may encourage you to drink more than if you drank water alone.

However, most of us probably don’t need anything except water. Milk has also been suggested as a good post-exercise drink containing plenty of water, minerals and protein to support recovery.

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In Conclusion...

The general rule to remember is:

1. Electrolyte-containing drinks should not be used by most people to replace water for rehydration purposes;

2. However, they do have a place as part of a properly planned and delivered diet for serious and highly trained athletes; and

3. Energy drinks should never be substituted for sports drinks even by athletes who could benefit from using sports drinks.

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