Guest post by Paul Fairbairn, BSc (hons) in Sport and Exercise Science & Nutrition MSc student.
Whether you’re training for fun or competing for sport, a number of us will have still asked ourselves the question: “How do I push myself that little bit further?” A popular strategy to increase performance is the consumption of sports drinks. But are these drinks essential or should we be avoiding them along with other soft, sugary beverages?
Sports drinks are often advertised through all kinds of media with messages such as “specifically formulated to help you perform at your best”. It’s very important to consider the different types of sports drinks, and what kind, if any at all, is suited for your particular physical activity.
The difference between sports drinks and water is that, typically sports drink will contain carbohydrate in the form of glucose (a simple sugar), alongside electrolytes such as sodium, potassium, magnesium, chloride, calcium, and phosphate. The primary source of energy for the human body is carbohydrate. So as we exercise our body uses up its carbohydrate stores, as well as losing essential electrolytes through sweat. When the body is depleted of carbohydrate it brings about a sudden fatigue often referred to as “hitting the wall”. This is where sports drinks come in as they provide the body with a carbohydrate and electrolyte boost to keep the body fuelled during longer periods of exercise.
There are three main types of sports drink: isotonic, hypertonic and hypotonic. And each of these is defined by its composition of carbohydrates and electrolytes:
Isotonic drinks – These contain similar concentrations of electrolytes and sugars to those found in the human body. This would be around 6-8g of sugar per 100ml. A standard 500ml bottle would therefore need to contain the equivalent of around 30-40g of sugar or 7.5-10 teaspoons. These tend to be the preferred choice for athletes.
Hypertonic – These contain a higher concentration of electrolytes and sugar than the human body. They have a sugar concentration of 10g+ per 100ml, so 50g+ of sugar per 500ml bottle and a whopping 12.5+ teaspoons. These are normally consumed after exercise to meet the increased carbohydrate requirements during ultra-endurance events.
Hypotonic – These contain a lower concentration of sugar and electrolytes than the human body. Which is around 2-4g of glucose per 100ml or 10-20g of sugar per 500ml bottle (2.5-5 teaspoons). These are more commonly used as a general thirst quencher in shorter or less strenuous exercise.
Sports drinks have been shown to increase performance in endurance activities, examples of which would be marathon running, long distance cycling and triathlons. There is also evidence to validate their use in sports such as tennis, football and rugby, however this is much less conclusive. Essentially any activity that requires someone to perform strenuous exercise for 1 hour or more could benefit from the use of sports drinks.
The evidence supporting their use for shorter bouts of exercise is fairly limited. If you consume sports drinks during short duration or low intensity activities, you are in danger of ingesting an unnecessarily high amount of sugar and salt. Therefore for activities of this nature drinking plenty of water to keep you hydrated will be sufficient.
Something else we need to consider is whether sports drinks are the only answer to exercise fatigue? Due to impressive marketing, you would be forgiven for thinking sports drinks contain magical ingredients, when in reality carbohydrate and electrolytes are available in every day foods. These include whole grains, potatoes and fruit to name a few. Consuming adequate amounts of these in our diet will go a long way to providing the necessary fuel we need to perform at our best. If your chosen activity falls into the endurance bracket and you require that carbohydrate and electrolyte boost, there are alternatives: coconut water, beetroot juice and the humble banana all provide simple carbohydrates and electrolytes. You also have the option to create your own sports drink at home. Glucose and electrolyte powders are readily available in most sport supplement stores, or you could also use the following household ingredients:
- 500ml of liquid (this could be plain water, coconut water or iced herbal tea)
- Honey to provide the sugars. 6-7 tbsp would match the sugar content of your average isotonic drink, however the amount can be tailored to your own requirements. I would suggest starting lower than this and adding more if you feel you need to.
- A pinch of sea salt
- A fruit juice or cordial of your choice to add flavour (optional) remember to keep in mind the sugar content of the added ingredient
The advantages of making your own drink are that it’s much cheaper and you can tailor the amounts needed depending on the specific needs of your chosen activity. Additionally we all have our own varying activity levels and sweat rates which will influence our requirements during exercise.
To conclude, sports drinks can be a useful source of fuel to give your body what it needs during long and/or intensive exercise. However it’s important to be aware that they also contain large quantities of sugar and salt. Therefore it is recommended that their use be limited to activities and sports requiring a high level of endurance. Before using sports drinks really consider what kind of activity you are taking part in, and if you really need the carbohydrate boost they give. Consider your diet too; sports drinks may help squeeze that extra bit of effort out, but they should be used as an enhancement, not as a substitute for a healthy balanced diet.
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Jeukendrup, Asker. ‘A Step Towards Personalized Sports Nutrition: Carbohydrate Intake During Exercise’.Sports Med 44.S1 (2014): 25-33.
Peltier, Sébastien L. et al. ‘Effects Of Pre-Exercise, Endurance, And Recovery Designer Sports Drinks On Performance During Tennis Tournament Simulation’. Journal of Strength and Conditioning Research27.11 (2013): 3076-3083.
Stellingwerff, Trent, and Gregory R. Cox. ‘Systematic Review: Carbohydrate Supplementation On Exercise Performance Or Capacity Of Varying Durations. Appl. Physiol. Nutr. Metab. 39.9 (2014): 998-1011.