The fridges at every gym, supermarket, corner shop and garage are filled with brightly coloured sports and energy drinks. They claim to enhance performance and help athletes replace water, electrolytes and energy during training or competition, but are they really needed? Are they all the same? And are they being used for the reason they were designed?

Types of Sports Drink

There are three main types of sports drink on the market. They all contain water, electrolytes and carbohydrates but in varying amounts.

Isotonic Drinks have the same osmolality (or concentration of dissolved particles), as the body’s own fluids, are easily absorbed and are designed to be drunk both before and during exercise. Examples of Isotonic drinks are Lucozade Sport, Poweraid and Gatorade. These contain 6-8% carbohydrate (around 60cal/250ml) as well as sodium. Isotonic drinks are commonly used in team sports and also in medium and long distance running.

Hypotonic Drinks have fewer particles than body fluid and are absorbed faster than plain water. Lucozade Sport Hydro Active is an example of a hypotonic drink containing just 1-3% carbohydrate and so providing less energy than its isotonic equivalent. A hypotonic drink is valuable when you are sweating but are not involved in vigorous physical activity demanding energy replacement. Their downside can be that they make you feel bloated and full. Hypotonic drinks are popular with jockeys and gymnasts who are looking to keep their weight down. They are also used by football players.

Hypertonic Drinks have a high osmolality than body fluids are absorbed slowly and are best taken as recovery drink after a workout. Hypertonic drinks have a carbohydrate concentration of over 10%. Energy drinks including Redbull and soft drinks like coke or lemonade come into this category as well as Lucozade energy. This level of carbohydrate will slow gastric emptying rate and actually decrease fluid absorption making them totally unsuitable for use before or during exercise.

Also on offer are

Vitamin Drinks – where as sports drinks are formulated to replace lost fluids and electrolytes and provide carbohydrates, vitamin drinks claim to also provide vital vitamins and minerals for overall daily health.

Sports Energy Drinks – these are like sports drinks but also claim to boost mental and physical power during exercise. They are generally similar to the isotonic drinks but include caffeine or other stimulants with suggested performance-enhancing effects. The jury is out on their effectiveness as some research shows that vitamin supplementation can slow response times.

Energy Drinks – as well as sugar they contain substances that act as nonnutritive stimulants, such as caffeine, guarana, taurine, ginseng, L-carnitine, creatine, and/or glucuronolactone. They are not exclusively marketed for sports use.

Coconut Water – sold in most gyms coconut water is the new sports drink trend. Naturally refreshing, it has a sweet, nutty taste and contains easily digested carbohydrate in the form of sugar as well as vital minerals. It has fewer calories, less sodium, and more potassium than a sports drink. Plain coconut water could be a better choice than sports drinks for amateur athletes but does contain ~50cal/250ml. It is not as beneficial for professional athletes due to its low sodium content.

Recovery Drinks – Research has shown that what you eat right after you working out, and up to two hours later, can drastically improve muscle recovery times. Recovery drinks are generally hypertonic and contain protein and carbohydrate in ratio 1:2.

What research shows

The bulk of the research shows that unless you are doing strenuous exercise for over 60minutes, specialist isotonic sports drinks offer no benefit over plain water. It is only after 90minutes that it becomes important to replace electrolyte losses and boost energy. However there is some evidence that consuming an isotonic sports drink can increase stamina and drinking flavored drinks may boosts the amount of fluid consumed during exercise both of which are beneficial.

Vitamin drinks are of no benefit over plain water. Many sports and energy drinks contain several B vitamins, vitamin C, calcium, and magnesium. There is no advantage to consuming these vitamins and minerals in drinks, if they are being obtained from eating a well balanced diet. There is little evidence that athletes have increased vitamin requirements.

Harmful effects of sports drinks

Most sports and energy drinks have a pH in the acidic range (pH 3– 4). A pH this low is associated with enamel demineralization. Citric acid is also frequently included in sports and energy drinks and has also been found to be highly erosive on teeth.

High consumption of sports or energy drinks during light exercise may lead to substantial weight gain. For athletes who are required to meet weight targets or remain lean, consumption of sports drinks may cause problems with energy balance. Many of the latest drinks contain high levels of fructose and research shows that fructose may interfere with the body’s natural sugar regulation mechanisms.

The brain and muscles prefer glucose for energy because it can be used immediately, but to get the best from your body (or brain) that glucose needs to be supplied in a slow, steady stream. Large ‘dumps’ of simple sugars can have a dramatic effect on insulin levels and lead to depression and anxiety. They also wreak havoc on the immune system lowering the bodies natural resistance.

The sports drink industry’s answer to this criticism has been to replace some of the sugar with artificial sweeteners. The long term effects of consuming artificial sweeteners is not really known but regardless of this it is slightly strange that there should be demand for ‘energy’ drinks containing artificial sweeteners, which have been specifically designed to provide no energy.

The timing of sports drink consumption is absolutely key. Their high sugar content will cause a surge in energy in the 15-20 minutes after consumption but afterwards will cause energy levels and concentration to slump.

Energy drinks containing stimulants may be harmful if drunk in large numbers. Sports energy drinks carry a warning that they “should not be consumed by children”.

Cost

The cost of sports drinks has come down in recently. Most of the standard isotonic drinks are between 10p-20p/100ml which compares with bottled water at 2p-4p/100ml. Low calorie sports drinks are slightly more expensive at 20p-25p/100ml and Energy drinks can be anything up to £3.50/100ml. Recovery drinks are about 40p/100ml.

Reading Sports Drinks Labels

Copyright © 2013 Iowa State University

 Advice

Although convenient it is actually much better to tailor your food and drink consumption to your own personal needs, rather than buying off the shelf. Larder and Gym can help you devise an easy eating and hydration plan to balance your daily intake to your needs. It is very easy to make your own sports and recovery drinks and there has been a lot of new research which suggests that the combinations of nutrients in commercial brands, may not be the best.