How to Choose a Sports Drink
Updated On
March 7, 2025
By Jim Rutberg,
CTS Pro Coach, co-author of “The Time-Crunched Cyclist”, “Training Essentials for Ultrarunning”, and “Ride Inside“
What is a sports drink?
A sports drink is essentially water with stuff dissolved in it. Some drinks have lots of different kinds of stuff dissolved in them, some of which just waste space. There is only so much room to dissolve solutes in a drink. As a result, drinks with fewer ingredients can use more room for important things like carbohydrate and sodium. The simplest drinks are best. They are easiest on the gut and facilitate the transport of sugar and electrolyte across the semipermeable membrane of the intestinal wall.
Note: CTS has a partnership with The Feed, which carries a variety of sports drinks and other sports nutrition products. CTS does not have any affiliation with a specific sports drink brand.
Osmolality matters
The concentration of sports drinks is important. Osmolality is the total molecular concentration of everything in the drink—carbohydrate, electrolyte, flavoring, additives—per unit volume. When you change osmolality, you change how the drink influences the overall mixture in your stomach. That, in turn, influences how that mixture makes it into the intestine. Scientists formulate sports drinks to optimize the absorption of carbohydrate, fluid, and electrolyte. If the osmolality is too high because of additives, it may slow gastric emptying. When osmolality is lower it may encourages faster gastric emptying, depending on what else you’re eating and drinking. A sports drink consumed on an empty stomach is formulated to get into the intestine quickly.
If you are designing a sports drink to have a relatively low osmolality but you want it to deliver moderate to high amounts of sodium and/or carbohydrate, you have to eliminate other stuff to make room. That’s a big part of the reason we’ve seen drink manufacturers shift to drinks with shorter ingredient lists.
Impact of flavor, electrolytes, and mouth feel
The ingredients, primarily sugar, sodium, potassium, and flavoring, are in the drink for good reason. Electrolytes and flavoring make you want to drink more frequently and consume more fluid each time. There’s actually a lot more to the way your sports drink tastes than marketing mumbo jumbo.
A lightly flavored drink is preferable to a stronger one. When you consume half a bottle in one slug, the stronger-tasting drink becomes overwhelming. As a consequence, you stop drinking. A drink that tastes almost watered down when you are at rest will taste just about right when you are exercising. This is why athletes have long diluted commercial sports drinks like original Gatorade. These days, many sports drinks are flavored to appeal to convenience store customers instead of athletes.
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Even taste components and mouth feel are important. A slightly tart drink will encourage you to drink more than an overly sweet one, and citrus flavors also increase the drive to drink. It should be no surprise, then, that almost every drink company has some version of lemon-lime and/or orange in its product line. In addition to the flavor, a sports drink needs to clear the mouth well. When a drink leaves a film in your mouth, as is often the case with overly sweet drinks, it’s not only unpleasant, but you’re not likely to drink again soon.
Tip: Don’t dilute sports drinks
Rather than dilute sports drinks, it is better to find a drink with a lighter taste so you can comfortably consume it at full strength. The reason you don’t want to dilute heavily flavored commercial sports drinks isn’t really because doing so lowers the concentration of sugar in the drink but because it reduces the sodium concentration. Again, this is relative to all the other foods and fluids you are consuming, but if you are consuming a sports drink with the primary goal of staying hydrated—that is, maintaining proper fluid and electrolyte levels—then consuming a watered-down drink provides a lot of fluid and reduced sodium, which over time could contribute to inadequate sodium replenishment in relation to fluid intake.
What to look for in the best sports drinks
- Multiple sources of carbohydrate: Different sugar molecules take different pathways through the intestinal wall. When you consume only one type of sugar you are only utilizing one set of “gates”. By consuming multiple types of sugar you can utilize more gates simultaneously. This means you will transport carbohydrate into your bloodstream more quickly.
- Citrates: When you read the ingredient list, look for sodium citrate and potassium citrate rather than or in combination with sodium chloride and potassium chloride. Citrates are easier on the gut and help increase the absorption of fluid.
- Sufficient electrolytes: While there are low-sodium versions of sports drink, if you’re consuming a sports drink with the intent of enhancing hydration status you want to consume 500-700mg of electrolytes per hour. That doesn’t all need to come from your sports drink (foods supply sodium, too), but low-sodium sports drinks make it less likely you will consume sufficient electrolytes.
- Carbohydrate appropriate to your goals: There are high-carbohydrate (approx. 20+ grams/500ml bottle) and low-carbohydrate (approx. 20 grams or less/500ml bottle). The lower carbohydrate drinks are preferred if your primary goal is hydration. If you are participating in longer endurance events and want to consume a larger proportion of your carbohydrate energy via drinks, try the higher carbohydrate solutions. Be aware, however, that overconsumption of higher-carbohydrate drinks may increase your chances of gastric distress.
Water vs. sports drink during endurance training and competition
Athletes and coaches vigorously debate what to eat and drink during exercise. Among the topics is whether athletes should consume only plain water, both sports drink and water, or just sports drink. At CTS Cycling Camps, athletes start each ride with one bottle of plain water and one bottle of sports drink on the bike. At subsequent stops, athletes freely refill with either water or sports drink. Here’s how we advise athletes to decide what to put into their water bottles:
- Heat/humidity: Separating fluids from calories allows for greater flexibility with fluid consumption. In hot environments you want the ability to increase fluid intake. To do this, carry plain water in your bottles and consume calories and electrolytes from food in your pockets.
- Can you actually eat? During technically demanding or high intensity events, some athletes don’t feel they have time to reach for solid foods or gels. Sometimes they lack the skills to reach for and consume food, but they can access their water bottle. In those cases, sports drinks may be the best or only way for the athlete to consume fluids, electrolytes, and calories.
- Will you actually eat? At the other end of the spectrum from high intensity workouts and events, ultradistance athletes sometimes get tired of eating. They get flavor fatigue from consuming lots of the same foods over many hours. Sometimes they get texture fatigue, meaning the thought of crunchy or gummy foods becomes unappealing. Sports drinks – especially those with light flavor profiles – can offer a good alternative.
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About the Author
Jim Rutberg
CTS Pro Cycling Coach
Jim Rutberg is a seasoned coach and endurance athlete with over two decades of experience, having co-authored ten influential books on training and nutrition, including “The Time-Crunched Cyclist” and "Ride Inside." His unique blend of academic knowledge, elite racing experience, and hands-on coaching at CTS positions him as a leading expert in endurance sports, dedicated to helping athletes reach their highest potential while balancing family life and personal passion for cycling.
Comments 28
How do I determine osmolality of a given drink?
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Great article! I really like Scratch Labs Wellness Hydration Drink Mix for hydration purposes as it has a good ratio of Potassium to Sodium. I dilute it out twice as much as suggested on the label since I drink close to 1L fluids/hr during hot runs and the mix was technically created for rapid rehydration. I am going to try and recreate the mix myself using sugar, Potassium Citrate and Sodium Citrate plus some lemon/lime flavoring. I haven’t decided if I will add any Calcium or Mg yet. Please let me know if anyone else has tried making their own drink mix!
I’m glad you don’t just “spoon feed” me here on what drinks to pick but give the important components of why to pick over whatever my needs may be at the time. No bones to pick here!
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Hi Jim and staff,
This article is “ok”…. The title promotes how to choose a hydration beverage; but seems to fall short of actually breaking down various drinks and their respective osmolarities, to choose from. Which is apparently why you get additional conributions in the comments section with personal antecdotes, in addition to confusion on uncovered but related topics which could have been covered in the article.
Anyways you also have syntax errors and makes the article less intuitive to understand. I looked to contact you personally but there is no direct email available. You need a content and language editor (I commented on a previous article) and I would be willing to take on that role remotely.
Honestly I’m hoping the coaching services are better than the articles. I have used one of your coaches previously – the same program the last 3 years with some success.
Author
You’re welcome to contact me directly at jrutberg@trainright.com.
Jim Rutberg
My understanding is that Stevia is a better alternative to sugar than other options as it is a natural product derived from a plant. The aftertaste is not appealing.
With all the hype, LMNT also includes Stevia as do BioSteel products.
If there are any electrolytes which don’t contain Stevia, I’d like to know and try them.
If you’re doing a 10k run, stevia might be fine, but this would be a huge mistake in a longer event where you need to consume calories. Why? Stevia is zero calorie sugar substitute and provides no “energy” to power your muscles. Various sugars and polysaccharides are used in sports drinks to provide full for exercise.
Sugar is just as natural as stevia. Sugar is made from the sugar cane plant. Stevia’s only benefit over sugar is that it has no calories which is terrible if you’re trying to gain energy, ie calories, from what you are eating and or drinking.
can you give some specific examples of the drinks you feel do a good job at the different percentages you spoke about. simplify this for us and just give me a few choices to try??
Great write up and such a nuanced topic. The plus side is there are many more tools today that assist in making those determinations alongside consultation with a nutritionist. Nix Biosensor and other such tools allow to calculate sweat rate and electrolyte consumption. Many CGM platforms out today allow for proper targeting consumption of nutrition during events. These are all tools though and really need a nutritionist to guide through initial discovery and then finally race/event planning. Re-assessing these targets need to be done as age introduces new challenges at different stages in life.
What are your thoughts on the keto, low carb energy powders?
I have had good results using them for my training. I try to eat low carb and these have helped me to stay within my goals.
Thank you
Author
Brad,
To be honest, I’m conflicted about answering your question. On one hand, if the keto/low carb drink is working for you and carbohydrate-rich drinks were not, then I’d say stick with them. On the other hand, I haven’t seen compelling evidence that low-carbohydrate drinks or drinks that promote nutritional ketosis improve endurance cycling performance. At best, they appear capable of achieving parity with carbohydrate-rich drinks, but they come with greater complication (can you always rely on having that special drink?). Your body is very good at using both fat and carbohydrate to fuel aerobic exercise, and maximizing the rate of fat oxidation happens naturally as a result of aerobic training. The best rationale I’ve seen for low-carbohydrate drinks is for people who struggle with gastrointestinal distress after consuming higher volumes of carbohydrate during exercise. Even if that’s the case, I’d encourage training the gut, as you can adapt to consuming and processing higher volumes of food, particularly carbohydrate. The best scenario is to use training and nutritional strategies to maximize your ability to use both carbohydrate and fat for fuel, rather than using a deprivation strategy to limit your fueling options. – Jim Rutberg, CTS Pro Coach
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Could this not cause dehydration “if you are participating in longer endurance events and want to consume a larger proportion of your carbohydrate energy via drinks, try the higher carbohydrate solutions” – in that the water will be diverted away from say muscles via the veins into the gut to create the correct ph level (osmolality) for absorption? The goal I suppose is to ensure the drink remains isotonic.
Paddy, there are some physiologic principles that may help address what you are asking. You may be correct in that if you eat a lot, blood is diverted to the gut to absorb the food, and this could reduce the blood flow to exercising muscles. To clarify some of your other statements: First of all, if you ingest just carbohydrate (CHO) with water, once the CHO is taken up into cells and metabolized, the water ingested with the CHO is in your system as pure water. Secondly, osmolality and tonicity are NOT the same. CHO in solution has osmolality, but, as noted above, once the CHO is taken up into cells and metabolized, the net effect is that you have ingested pure water (no osmolality). Tonicity on the other hand represents the concentration of solutes that can cause water to come out of cells. It is usually made up of electrolytes. Most of the water lost with exercise is via sweat, and the tonicity of sweat is actually around only about ¼ of the tonicity of our body fluids (i.e. sweat is hypotonic in relation to normal body fluids). That is presumably why the electrolyte content of sports drinks is restricted to ensure that the tonicity of the drink is not too high. Ingesting isotonic fluids to replace the hypotonic fluid lost in sweat would result in plasma and body fluids becoming hypERtonic (higher than normal tonicity), causing water shifts out of cells and making the athlete feel worse. The approximate concentration in sweat of substances that contribute to tonicity is around 35 millimoles per litre (about half of which is from sodium (~ 402 mg of sodium per litre). Looking at the content of Nuun SPORT Hydration tablets, and dissolving it into the recommended 475 ml of water (final volume roughly 500 ml) yields a tonicity of around 37.5 millimoles/litre, VERY close to the tonicity of sweat. Other hydration drinks have less sodium, and are relatively hypotonic (less concentrated) than sweat. Thirdly, pH level and osmolality are NOT the same thing, and the mechanisms that regulate pH and osmolality in the body are not the same. Hope this helps.
What about those who claim you should NEVER use simple sugars, even in sports drinks, only “complex carbs”? Any real rational to that?
I always go with one plain water bottle and one with Nuun Performance when I am on bike rides over 2 hours/over 75 degrees. Otherwise just water. I ensure both are gone every 2 hours. The last hour/cooling down I had an extra tab to my water.
I have no idea why I came up with this? However, I find it works and the extra sweet taste right at the end triggers something that makes me want to drink. When the water is plain, I find myself not drinking as much. Worse yet, probably moving towards the ole recovery beer at the finish line with others. Nuun seems to stave off the need for the recovery beer. Try it, perhaps it will work for you too!
The difference for athletes is in how fast they are absorbed and processed. Simple sugars go faster than complex carbs. So it depends on your needs. IME, a mixture works best, but everybody’s experience and needs are different.
Yeah, plain water is only good for short rides. After that, it starts just sloshing around in my gut.
Many sports drinks are adding non nutritive sources of sweeteners, like Stevia. I had a “discussion” with HEED at Interbike. My feeling, based on the research, is that these actually make you crave sugar and may be associated with other rare side effects. Yet many are including them in their drinks and electrolyte supplements. Not Bonk Breaker! What are your feelings.
just watch for Mag Citrate of longer events… unless want to clean out bowels. Too many companies use fructose which in long or hot events since hows its digested can cause GI issues in many not all. Most people add too much CHO per bottle so its good to see your rec on it. I go with 4-8% solution depending on temps. Also need to keep in mind starting and finishing temps
That’s good, Matt. From all the data I’ve read, the optimum concentration is 6% to 8% of a 2:1 ratio of sucrose and glucose. I also add electrolyte tablets for the flavor. I get the sugars from Amazon. A LOT cheaper than Gatorade.
I wish support drinks wouldn’t use Stevia at all. ! What good is it??! in fact, gastroenterologist, confirm, it is not Gastro healthy.
Through my own experiments , my Gut agrees. Therefore, I will not drink, nor recommend any Sports drink that contains Stevia. It’s so frustrating most sports drinks have Stevia, despite saying no sugar added. But, I just read the fine print.
My wife and I are avid road cyclists and have used Hammer Heed for nearly twenty years now. We rode for years in Maryland along the Chesapeake Bay hills and western Connecticut where every road is hill climb, doing sub-five hour century rides. Temperatures were often in the mid 90 degree range and humidity % to match. We have never had any gastro problems using Heed nor any such Heed-induced “sugar craving” that you mention.
Heed has a very mild flavor and a very minimal “sweet” taste which we find more conducive to insuring that we keep hydrated with it.
Regarding “rare side affects”, I think one can safely say that any food source can cause “rare side affects” for some of the population that use it.
I’ve also used HEED for 20 plus years in the Dallas- Forth Worth area where summer temperatures can get above 100 often. I’ve used it the many times I’ve ridden the Hotter n’ Hell Hundred at the end of August. I haven’t had the gastro problems either, and any end of ride sugar cravings I may have after a long ride I chalk up to my body wanting to refuel. (Refueling not just with sugar, of course)