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Race Fueling

Sports Drinks Are Cutting Out Sugar. Is That Good for Endurance Athletes?

The latest breed of sport drinks are sucking some of the sugars out of their products. But don’t go rushing to fill up your bike bottles with low-carb drinks just yet.

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While sipping plain old water is always a good choice for general hydration needs in training and races, there are many cases when it’s better to spike your water bottle with some extra juice. Enter the sports drink, whose aim has traditionally been to provide bodies in motion with three things: water, fast-acting carbohydrates (sucrose, dextrose, maltodextrin and their ilk), and electrolytes to help you go faster for longer. With all those cinematic commercials featuring famous athletes guzzling colorful liquids, sports drinks have been well marketed for many years now.

But what’s the best sport drink for triathlon? This is certainly a hot topic among hard-charging athletes. What tastes great and works well for one person is much too saccharine for another; your training buddy may swear by one formulation, but another might say it’s a one-way ticket to a stomachache.

The original pitch for high-sugar sports drinks stems from research showing their faster-acting sugars can improve exercise performance. They help athletes keep up the pace by slowing down the drain of liver and muscle carbohydrate stores, the primary energy source for high-intensity exercise. But there’s a newer breed of sport drink, one which takes some of the carbs out of their products to maintain better hydration without the stomach revolt.

Certainly, low-sugar drinks make sense for days off, but things get complicated once you’re exercising for a serious chunk of time. Let’s take a deep dive into low-sugar sports drinks and how they fit into a triathlete’s hydration strategy.

RELATED: Triathlete’s Complete Guide to Nutrition and Fueling

What are the features of low-sugar sports drinks?

Many traditional options, like the original Gatorade formula, provide about 21 grams of fast-digesting simple sugar carbohydrates (5 teaspoons) in a 12-ounce serving, along with roughly 150 milligrams of sodium and a modicum of potassium. But other options have fewer carbs per serving, if any at all. A nuun Sport tablet, for example, has just 4 grams of carbs and 15 calories along with 300mg sodium and 150mg potassium. Gnarly Hydrate contains a mere 30 calories and 4 grams of carbs plus 250 mg sodium. A serving (2 scoops) of Osmo Active Hydration supplies 17 grams of carbs, mainly from cane sugar and dextrose, and 260 mg of sodium. Liquid I.V. Hydration Multiplier contains 11 grams of carbs and a lofty 500mg of sodium.

One of today’s buzzwords in the sports drink market is osmolarity, a term that refers to the total concentration of dissolved particles in a liquid. Water travels around your body via osmosis: Water molecules squeeze through cell membranes, moving from areas of low osmolarity to areas of high osmolarity. As your body absorbs the sugar from a sports drink from your intestines, water molecules are absorbed alongside. So if you ingest something of higher osmolarity, like fruit juice or a higher-carb sports drink, it likely won’t be absorbed as quickly. Until it is diluted to a lower osmolarity by pulling water out of your blood and into your intestines, it sits in your stomach and sloshes around, which could, in theory, lead to gastrointestinal distress. Low-carb sports drinks claiming to be “lower osmolarity” or hypotonic advertise that they provide faster hydration with less risk of you clutching your stomach and hunting for the nearest port-a-potty.

In addition to their lower carbs and, in turn, lower osmolarity, this newer style of sports drinks emphasize their enhanced electrolyte content, designed to replace what’s lost in sweat and prevent hyponatremia, a dangerous drop in blood sodium levels that can occur when athletes in motion drink water to excess. Many brands will supply about 40 to 50 percent more sodium than traditional options.

Flavoring your water with a low-sugar tablet or powder also makes it more appealing to take bigger sips, which encourages better hydration practices.

And let’s not overlook the societal shift in how sugar has become a nutritional boogeyman. This shift has had an impact on today’s shrewd, health-conscious athletes as well. Consequently, many triathletes are reconsidering how much sugar they want in their bottles, even during exercise, believing less might be a healthier choice.

Should you switch to a low-sugar sports drink?

While these drinks may have some advantages, some sports dietitians and exercise physiologists are skeptical of the purported benefits.

Some hydration experts question whether relatively small differences in osmolarity have a meaningful impact on how well a sports drink is tolerated. Individuals might have differing abilities to tolerate various carbohydrate solutions. A study published in the International Journal of Sport Nutrition and Exercise Metabolism demonstrated that sports drinks of all concentrations were absorbed slightly better than plain water, but also reported differing levels of “gut comfort,” with the lower-carb hypotonic (low osmolarity) drink used in the trial sitting easiest on the stomachs of participants. This investigation found that people reported more GI complaints when consuming a regular sports drink during an 18-km run than when they took in water and there was no noticeable difference in performance.

Still, we need to see more studies conducted on athletes taking part in various sports to get a better sense of what amount of carbs and what type are best tolerated. It should be noted that in some cases athletes can train the gut to be able to take in a higher concentration of carbs from a drink without stomach revolt. In the end, the degree of tolerance to different carbohydrate levels in drinks is likely highly variable among individuals and something that needs to be tested through trial and error.

What about refueling during your weekly long run, century bike ride or multi-hour race? From a performance standpoint, carbs are especially useful when your race distance stretches beyond an hour and have been shown in numerous studies to prolong endurance via a few mechanisms, including sparing precious muscle glycogen. And both runners and cyclists seem to be able to burn the same amount of supplemental carbohydrates during exercise. The American College of Sports Medicine suggests consuming 30 to 60 grams of carbs per hour of exercise, which you can get from either a sports drink or from other products like gels and energy bars. Roughly 16 to 32 ounces of regular sports drink per hour will give you this necessary carbohydrate recommendation. Less highly trained athletes may need more carbohydrate energy as their bodies aren’t as well adapted to the task at hand. Proponents of lower-carb beverages, however, suggest liquids be used mainly for hydration purposes and outside-the-bottle carbs be used for fuel.

RELATED: The Triathlete’s Guide to Race Fueling for Every Distance

Yet energy-rich food can be hard to digest. You need to remember that sucking back concentrated products like a gel or chews pulls water into your stomach to dilute it, impairing fluid absorption. This is why you need to chase them down with a sufficient amount of a carb-free solution, such as a very low calorie sports drink or just plain water to expedite digestion. The faster you move, the more difficult it becomes to refuel with solid foods. This is why some triathletes rely heavily on liquid energy from higher carbs sports drinks, especially when picking up the pace.

With that said, low-calorie sports drinks can be well-suited for ultra-length endeavors when you have ample time to eat and digest enough carbs from other sources to maintain a necessary pace and where too much liquid sugar over the long haul can certainly bring on GI distress.

Frustratingly, we have very little in the way of randomized studies that compare the percentage of carbohydrates in drinks with various performance metrics when total carbohydrate intake is kept constant. So would consuming 60 grams of carbs per hour of exercise entirely from a higher carb drink result in a different performance outcome than obtaining the same number of carbs from a combination of lower-carb sports drink and some other source of fuel?

While science is continually uncovering new ways that an excessive intake of added sugars can derail our health, the health ramifications associated with high added sugar intake are not of concern when you’re taking in that sugar during bouts of sustained exercise. A 2016 review published in the International Journal of Sports Nutrition and Exercise Metabolism, for example, found that when higher sugar sports drinks are used to fuel endurance exercise beyond 60 minutes in length they do not abolish the energy deficit created by working out. Sugar is only a problem when you consume too much as part of your normal diet and not as part of a smart fueling strategy where it serves a specific ergogenic function.

But, yes, that sugar which is okay in cases when you need sustained energy for activities like a prolonged run or ride, is much less useful for more pedestrian workouts or even bouts of intense intervals that may not last longer than an hour or so; you can pull from your body’s energy stores without consequence. And there is some evidence that if a higher carbohydrate meal was consumed before working out there is no significant benefit of consuming supplemental carbs for aerobic activities lasting up to 2 hours. This is certainly where low-carb sports drinks can come in handy, something that promotes better hydration but won’t deliver the unnecessary sugar rush. Ditto for just sipping during the day for overall fluid consumption. And, it shouldn’t go without saying that a huge number of regular sports drinks are sold to people who really don’t need them. For instance, they are marketed aggressively to teenagers and, in turn, they are heavy consumers which is likely contributing to the troubling obesity rate in this demographic.

As for ingesting sports drinks with extra sodium this is likely only particularly useful when you’re exercising for longer than two hours or if you have unusually large salt losses during exercise, which can occur if pushing the pace in very hot, humid conditions or you are colloquially known as being a “salty sweater.” Although, somewhat surprisingly, there is little research to show that salty sweaters glean more benefit from higher sodium drinks than do those who finish their workouts without the white stains on their kit. Most people get more than enough sodium from their diets so there generally is not much need to get extra from a sports drink throughout the day when not exercising.

There is very little compelling data that taking in other electrolytes, namely potassium, magnesium and calcium, during activity does much of anything, especially if you are already getting enough of these in your diet.

Athletes can choose products that glean their sweetness from low-calorie inclusions like sugar alcohols, stevia and monk fruit extract instead of sugars but for some people these can lead to the GI issues that low-carb drinks are aiming to abolish in the first place. And not everyone loves the taste of these sugar alternatives. If you don’t like the taste of the product, chances are you probably won’t be drinking much of it which can impact proper hydration.

RELATED: How to Train Yourself to Drink

The bottom line

As with anything nutrition related, a one-size-fits-all mentality rarely works. Many athletes would be best served to experiment with a variety of drinks to figure out what works best for them in certain situations. These lower-sugar sports drinks might be worth a try if you’ve had stomach issues with traditional sports drinks but need something more than simple water.

The evidence is not clear to say that lower-carb, higher electrolyte sports drinks are a game-changer, but at the very least they do broaden your options when you’re figuring out your game plan to hydrate and fuel.