The high-carb revolution is here. As runners push the limits of how many grams of carbs they can ingest during training and racing, nutrition brands are responding to see how many carbs they can pack into their products. Queue high-carb drink mixes.

New sports drink formulations are designed to make a can of Coke look like child’s play from the 1890s. The philosophy is that supplementing your race nutrition with liquid calories is an easy approach to consuming a level of carbs during exercise once thought to be attainable only by those with superhero guts.

For many years, exercise physiologists and sports nutritionists recommended that runners and other endurance athletes consume no more than 30 to 60 grams of carbohydrates per hour of activity. This was enough, they believed, to give working muscles a necessary supply of  precious fuel. But any more, so the reasoning went, would increase the risk of bloating, nausea, diarrhea, and other gastro woes without a substantial boost to performance. The risks outweighed the rewards was the thought of the day.

How things have changed. Modern day research and anecdotal evidence from athletes, including pro distance runners and almost every professional cyclist in the peloton, show that higher carb intakes are certainly possible—up to 100 grams per hour, or even higher—and without gastrointestinal explosion. Remarkable digestive feats, indeed.

This hunger for more carbs has led many of the big players in the sports drink world to design products that pack in a lot more of them. Spiking your water bottle with 80, 90, or even 100 grams of carbs is now easier than ever, and it may push you to the finish line in record time.

Are high-carb sports drinks the game-changer you need? Let’s look at the nuances behind using these formulations for distance running.

The High-Carb Philosophy

It’s likely no coincidence that as carbohydrate intake has shot upwards, we have begun to witness monumental improvements in power outputs and finishing times. By supplying your hard-working muscles with an impressive amount of their preferred fuel source, there are many reasons to be hopeful that these newfangled high-carb drink mixes can help produce hero runs.

“Carbohydrate ingestion during exercise can help stave off the depletion of glycogen, the stored form of carbohydrates in our muscles and liver,” says Marni Sumbal, CSSD, MS, RD, owner of Trimarni Coaching and Nutrition and 24-time Ironman finisher. “This allows athletes to exercise harder for longer before fatigue sets in.”

By going bigger with the carbs, athletes like Sumbal know that the chances you’ll redline your precious glycogen stores in your muscle fibers and tank your blood glucose is considerably less. Also, there could be an advantage to simply tricking your brain into thinking that more fuel is coming (as has been demonstrated with studies of swishing a sports drink in the mouth and then spitting it out).

An intriguing 2024 study in the Journal of Applied Physiology used real-world data to simulate how many grams of carbs per hour elite men and women marathoners would need to consume to run a sub-2-hour marathon. (It’s a hypothetical scenario, just go with it.) The researchers found that your typical elite male marathoner would need to take in 93 grams of carbohydrate per hour, while an average elite female athlete would need 108 grams per hour—significantly higher than traditional sports nutrition guidelines—to push faster than the 2-hour marathon mark.

Endurance athletes have been experimenting with higher carb intakes for a while—Kilian Jornet went public about pushing the limit up to 100 carbs per hour in 100-mile races in 2022. But 2024 felt like a tipping point: Ultrarunner Rod Farvard, for example, credits dialing in his race nutrition to around 100 grams of carbs per hour for his breakout win at the Canyons 100K last spring, followed up by his runner-up finish to Jim Walmsley at Western States; ultrarunner David Roche credits much of his 2024 record-breaking run at the Leadville 100 with his ability to inhale upwards of 120 grams of carbs during each hour of his 15 hours on the route. It’s a fueling strategy likely not endorsed by his dentist.

There can be clear advantages to getting some or most of your carbs from a bottle versus, say, choking down multiple gels and bars. “Because sports drinks are designed to be mixed in water, this provides an optimal formulation to enhance digestion and absorption,” Sumbal says. “In order for the nutrition you consume to be used during exercise, it needs to be emptied from the gut, taken to the bloodstream, and then used by the working muscles.” Sports drinks are one of the best ways to accomplish this.

But does carb-crushing lead to better performances when it counts most? Unfortunately, we don’t yet have much in the way of dose-response scientific literature when it comes to ultra-high-carb fueling. Let’s just say that the real-world experiences of elite athletes who are churning out impressive power numbers for longer are much more compelling and worth paying attention to.

Remember, though, that elite athletes were already super fast before they started pounding back more liquid carbs. But some of the race times we are witnessing suggest the gains might be more than marginal.

Yet, high-carb sports drinks may have less value for four-hour marathon runners than for those blazing along almost twice as fast since the calorie burn per mile can be noticeably less. Hard-charging athletes need to fuel more during and after workouts to sustain themselves. It’s a bit self-perpetuating. And one should not forget that the limits of endurance depend on more than just your carbohydrate supply. Hydration, mental training, genetics, budget for super shoes—the list goes on.

How to Use High-Carb Drink Mixes Strategically

However, more is not always better. You need to be wary of using these high-octane sports drinks willy-nilly, as not every run requires mega carbs. If you’re only going out for an easier run that’s not going to push past the 90-minute mark you don’t need this kind of energy hit.

“Around two hours of continuous exercise, runners would benefit from consuming a more modest 60 grams of carbs per hour,” Sumbal says. “The longer the session, the more carbs that would be beneficial, and the more power and effort produced during the session, the higher the carb recommendation.”

In other words, the benefit of higher carbs comes from absolute exercise intensity and duration. If training duration exceeds two hours and involves a fairly high energy cost that will stress your glycogen stores, then this is the time where you can consider spiking your water bottle with more carbs and pushing past that 60-gram recommendation. That’s because, Sumbal stresses, the harder you work for longer periods, the more energy you need to consume to sustain that effort.

We’ve all watched the videos of runners crawling across finish lines after multi-hour runs. Would that have happened if they sucked back more carbs? It’s an intriguing hypothesis.

Start GI Training

Just like training for your biggest race, your body needs time to build up to handle a lofty carb intake. Chug back a bottle with 90 grams of carbs from the get-go and I wish you the best of luck. So how can athletes now consume almost double the quantity of carbohydrates previously thought possible? Mainly it’s about boosting gut tolerance, or what is being called “gut training.”

“The body is not designed to digest food under stressful situations like exercise. And as a result, if you expect your gut to be able to process a high number of carbohydrates each hour during exercise, you may end up with digestive issues,” Sumbal says.

She adds that the physical impact of running and jostling of organs can disrupt the digestive system, making runners more likely to experience digestive problems when fueling during exercise compared to cyclists. “But the gut is a muscle that can be trained.”

Feed training, she says, can increase your tolerance for consuming big amounts of carbs during exercise at high intensities. A 2023 systematic literature review published in Sports Medicine found gut training helps reduce the incidence of exercise-associated gastrointestinal symptoms during cycling by decreasing malabsorption of sugars in the intestine.

So, how do you toughen up your gut? “First learn where your sweet spot is,” Sumbal advises. She suggests discovering your current carbs-per-hour comfort level that gives you stable energy without digestive issues. From here, start working your way up by 5 to 10 grams of carbs per hour. For example, if you feel like 45g/carbs per hour is your sweet spot, try moving the goalpost to 50g/hour for your next long workout. Continue to work your way up until your gut is comfortable consuming the amount you feel you need to perform at your best during an important hard run like a multi-hour race. Luckily, many high-carb drink mixes are easily customizable, so you can add a little more as you go to build up tolerance so you aren’t sprinting to the nearest port-a-potty at mile 12.

Another part of the gut training equation is to make sure your overall diet isn’t too carb stingy. “Research shows that training with high-carb availability by consuming a high-carb diet to keep glycogen stores high and taking in carbs during exercise can increase the rate at which the body is able to utilize carbohydrates for energy production,” Sumbal says. In other words, not shying away from pasta, rice, and bread during periods when you’re training hard can make these high-carb drinks easier to stomach.

My Favorite High-Carb Drink Mixes

It’s time to think beyond Gatorade. These next-level sports drinks make it easier to go carb-crazy.

Skratch Labs Super High-Carb Sports Drink Mix

$42 for 8 servings

My pick: Raspberry

$0.05 per gram carb

Nutrition (7 Scoops): 400 Calories, 100g Carbs, 0g Fat, 0g Protein, 400mg Sodium

With Skrach Labs Super High-Carb, you can easily adjust the amount of mix you use to hit the carb numbers you want. That’s ideal if you are working up to handling a greater carb load. Use four scoops per 16-oz bottle and you’ll get nearly 60 grams of carbs an hour if you suck back the whole thing during this time. Use the suggested seven scoops, which will only give you eight servings per bag so, yes, more pricey, and you’ll load up on a whopping 100 grams of carbs.

Fortunately, the subtle berry flavor won’t overpower your taste buds—important if you plan on using lots of the stuff during a long run. The drink mix is powered by cluster dextrin, which, Skratch says, takes time to break apart as you digest it thanks to its unique structure, resulting in a steady release of energy which lessens the risk of gastrointestinal distress.

While it won’t turn into sludge when mixed with water—a definite risk with carb-dense powders—it still does not dissolve as effortlessly as the brand’s lower-carb mix. One option is to mix the powder with water in a blender and then pour this into your bottle. Even with the full seven scoops, one serving only contains 400 mg of sodium. Worth noting if you need more of this electrolyte to help offset losses.

Tailwind High Carb Fuel

$23.50 for 6 servings

My pick: Ginger Lime

$0.04 per gram carb

Nutrition (1 packet): 360 Calories, 90g Carbs, 0g Fat, 0g Protein, 680mg Sodium

Tailwind’s gingery drink mix dissolves surprisingly well (no choking hazard sugar clumps) and has a hefty 90 grams of fast-working carbs from maltodextrin, dextrose, and fructose in each packet to keep you going strong during high-intensity efforts. You’re instructed to mix the powder with 16 to 24 oz of water and nurse this over a one hour.

“When sports drinks use multiple forms of carbs it allows for higher oxidation rates by making use of different transporters so you can deliver more carbohydrate to your muscles per hour,” Sumbal explains. And that means giving your muscles more fuel and lessening the risk for GI problems. The 680 mg of sodium and 190 mg of potassium are higher than what you get from most other high-carb mixes, which can be useful for especially sweaty workouts. The drink mix is also available in lemonade flavor. While convenient,  the single-serving packets produce some extra waste.

Carbs Fuel Sports Drink Mix

$36 for 13 servings

Under $0.04 per gram carb

Nutrition (3 Scoops): 300 Calories, 75g Carbs, 0g Fat, 0g Protein, 500mg Sodium

Carbs Fuel entered the market with their budget-friendly high-carb gels, and now have set forth a carb-dense drink mix that also gives you more carbs for less. The multi-serving pouch provides runners with a large dose of carbs for a reasonable $3 per serving. If using the recommended three scoops, users will net 75 grams of carbs, 300 calories, and 500 mg of sodium per serving. Of course, you can use more or less based on your needs and tolerance.

It’s made with a blend of four different carbohydrates in a 1:0.8 glucose-to-fructose ratio, which is the ratio shown to increase oxidation rates and lower the risk for GI revolt. The neutral flavor will appease users who get burnt out on the saccharine taste of most sports fuel.

Maurten Drink Mix 320

$51 for 14 servings

$0.05 per gram carb

Nutrition (1 packet): 320 Calories, 80g Carbs, 0g Fat, 0g Protein, 245mg Sodium

Used by professional runners to take down marathon records—including Eliud Kipchoge when he sprinted his way through the first sub-2-hour marathon in history—Maurten is praised for providing lofty amounts of carbs without the digestive ramifications. Crucial to the success of the drink mix is the formation of a hydrogel when mixed with water. When this gel-like liquid hits the stomach, it helps the carbs empty from the stomach more easily. This should decrease GI problems while simultaneously enhancing energy delivery.

The product comes as a dry mix in two strengths: Drink Mix 160, with 40 grams of carbs per half a liter (16.9 ounces); or Drink Mix 320, which contains 80 grams of carbs. Because a gram of carbohydrates has four calories, the 160 and 320 refer to the calories in each mix. They also have a caffeinated option.

The downside? The stuff ain’t cheap (like most of these drink mixes), and most of us non-sponsored athletes will need to limit its use to important workouts and races. And sodium levels may not be enough to meet every sweaty runner’s needs.