When it comes to Sports Drinks, there are far too many choices!
Which sports drink has the most electrolytes? Which sports drink has the most sodium? Which sports drink is isotonic? What sports drink has the least sugar? Which sports drink is the best for hydration?
And most importantly, what sports drink is the best choice for optimal performance? Let’s have a look…
What are we looking for in a sports drink?
Ultimately, we’re looking for a product that helps meet our fuelling and hydration needs. Sports drinks should be designed with a combination of different carbohydrates, electrolytes and of course fluid to keep you hydrated and performing at your best. But not all sports drinks are created equal…
As a general rule, most sports drinks contain between 6-8% carbohydrate. So, in 100mL of the product (made up to the correct concentration), they contain between 6-8g of carbohydrate. Anything higher can delay the rate of your stomach empties which reduces the amount of fluid available for hydration (1). This delay can lead to an upset stomach and hunting for the toilet mid-race which is not ideal!
You can super concentrate up your sports drink in the one bottle, as long as you’re diluting it back down in your stomach by drinking lots of water.
The other factor to consider with carbohydrate is the type of carbohydrate the product is made of. We absorb different carbohydrates differently so it’s important to know what carbohydrate you’re using. I’m not going to dive deep into the science here, but the ultimate mix is a product which contains multiple different types of carbohydrates which are transported across the stomach wall differently to a) increase your fuel absorption and b) not cause gut upset c) promote hydration.
For the endurance athletes among us, training and competing in events >2hours, it’s also important to have a sports drink concoction that meets your overall fuel needs in combination with the rest of your plan. If you’re only using a single carbohydrate channel i.e. glucose, our absorption maxes out at 60g per hour. If your needs are higher than this (e.g. Ironman, elite/sub-elite athletes, speedy age-grouper), you’re going to want to invest in a product that utilises different carbohydrate channels i.e. fructose in its blend to increase your fuel delivery beyond this cap (1, 3). This mix of carbs has been shown to increase oxidation rates by up to 75% (4).
Sodium, potassium, magnesium and even calcium are often included in sports drinks, although evidence suggests sodium is the most beneficial to consume during exercise (1).
Sodium is added to a sports drink to drive thirst and encourage fluid consumption. It also promotes greater plasma volume retention and reduces urine output. However, at present, there are no clear guidelines for sodium intake during endurance exercise and there is also no clear link between sodium replacement and improved performance. There may be performance gains as a side bonus by preventing exercise-associated muscle cramps and/or hyponatraemia (low serum sodium) – both which are obviously performance limiting factors. This is obviously more important when the event is longer (and harder).
Most sports drinks contain between 10-30mmol/L of sodium which is actually not that high. 2 slices of bread contain more sodium than a 600ml bottle of sports drink! Add vegemite to your sandwich and you’ve smashed sports drink out of the park.
So how do you know how much sodium to consume?
The short answer is, we don’t really know yet. The best we can get to formulating an individualised plan is to do Sweat Testing with an Accredited Sports Dietitian to understand your unique sweat rate and sweat sodium concentration. This will allow you to find a sports drink and other products to more closely meet your losses during your event.
If you’re a heavy sweater, suffer from cramping or find yourself leaving salt stains on your clothes after a race or training session, consider investing in a Sweat Test.
Fluid and Osmolality
Sport drink provides fluid for hydration but when considering what product to use, you need to consider your overall event, the duration, intensity and your ability to consume the fluid in the first place.
The number one factor here in my books is taste. If you don’t like something, you’re less likely to drink it! Find a product that you like and enjoy drinking, because the other components can be easily be manipulated by a qualified Sports Dietitian.
We can’t step past fluid without briefly mentioning Osmolality…
Osmolality is a measure of the number of particles in the solution (per litre).
Isotonic means the solution has a similar osmolality to the body (290mOsmol/L)
Hypotonic means the solution has a lower osmolality than the body – less particles
Hypertonic means the solution has a higher osmolality than that the body – more particles
A lot of products today market themselves as ‘isotonic’ as this is the ideal for absorbing fluid across the gut wall. The more concentrated the solution (hypertonic) and the weaker (hypotonic) the solution, the harder it is to absorb.
BUT it’s hard to find information about a particular sports drinks’ osmolality
AND does it really matter?!
The answer…Not really.
Unless you’re solely relying on just sports drink for all of your fuelling and hydration needs (there are limited situations where you would actually want to do this?!), chances are you’re using a mix of water, foods, bars, gels, lollies etc during training and racing and these things all affect the overall osmolality in your stomach anyway. Moving on…
Sports Drink Comparison
To help you out a little, we’ve selected a few of the common sports drinks used and run a quick comparison for you…
Not all sports drinks are created equal. As you can see above, some contain low amounts of carbohydrate and/or sodium, some don’t contain a nice blend of different carbohydrates and some are just bloody expensive!
When choosing what sports drink is best for you, it’s all about finding the balance between your hydration and fuelling needs. Work with an Accredited Sports Dietitian to understand this for your particular event.
There is not one product out there that will meet the ideal formulation for you. Because the ideal formulation for use across different sports and situations does not yet exist. You need to determine what’s achievable, practical, accessible and find something you like the taste of. Then map out more of a global training and racing nutrition plan. This will likely include a sports drink, but also other foods and sports products to optimise your performance.
Then your homework is to practice!
Happy training 😊
1. Burke, L., & Deakin, V. (2015). Clinical Sports Nutrition (5th ed.). North Ryde, NSW: McGraw-Hill.
2. Bohl, C., & Volpe, S. (2002). Magnesium and Exercise. Critical Reviews in Food Science and Nutrition, 42(6), 533–563. https://doi.org/10.1080/20024091054247
3. Academy of Nutrition and Dietetics, Dietitians of Canada, and American College of Sports Medicine (2016). Nutrition and Athletic Performance. Medicine & Science in Sports & Exercise, 48(3), 543–568. https://doi.org/10.1249/MSS.0000000000000852
4. Jeukendrup, A. E. and Moseley, L. 2010. Multiple transportable carbohydrates enhance gastric emptying and fluid delivery. Scandinavian Journal of Medicine and Science in Sports, 20: 112–121.