When Sebastian Sawe burst through the two-hour marathon barrier last April in London, he awed the world. Analysts immediately began slicing and dicing his training protocols, his carbon-plated shoes and his nutrition. While you can’t undervalue the role shoe technology played in Sawe’s record-setting performance, nutrition was key, too.

According to reports, Sawe took in approximately 115 grams of carbohydrates per hour. While long-held recommendations surrounding carbohydrate intake makes that number jaw dropping, the thinking is changing. And while your customers are rarely at the elite level, understanding the latest sports nutrition theories is essential when they purchase products.

“We’ve learned so much in the past decade or so,” says Meghann Featherstun, RD, a certified specialist in sports dietetics, “and much has changed.”

Older, “traditional” recommendations for carb intake used to top out at about 60 grams per hour. But formulations have changed — and along with them, so have the limits.

“In the 1980s, drink mixes began appearing that largely consisted of glucose-based sugars,” explains Roxanne Vogel, PhD, director of research and education at GU Energy Labs. “They worked to provide energy and they were also easy to digest. But the upper limit was about 60 grams per hour or you’d experience GI distress.”

Along came the 1990s and the advent of gels, which revolutionized the fueling market thanks to their multi-transport carbohydrate system of glucose and fructose. While the sugar base changed, the thinking on grams per hour remained steady, around 60 grams per hour.

But recent research is turning much of that on its head. Researchers now know that athletes can push the grams per hour higher, delaying or even nearly eliminating the drop in stored glucose and keeping energy levels high enough to complete a long run or race. Beginning about 10 years ago, studies suggested that 90 grams per hour for events lasting at least two-and-a-half hours was reasonable.

Reaching the levels that Sebastian Sawe achieved – from 115 to 120 grams per hour – is also possible, in some circumstances and for some runners. The devil is in the details, however, and for runners seeking answers, it’s important to keep nuance in mind.

Inform and educate at retail

When runners begin working with carbohydrate supplementation, they should have two goals in mind, according to Featherstun: Supporting their training/racing, and preparing their gut. “You don’t get good blood flow to the gut when you’re running,” she says, “so you need to train your gut.”

With the idea in mind that most runners can handle more carbs than what previous thinking held, it’s worthwhile for them push boundaries a bit to understand their limits. This allows runners to gain confidence in their fueling plan so that on race day, nothing is left to question.

Retailers should know when to recommend a runner begin ingesting supplemental carbohydrates, like gels, chews or drinks. “I like to say replenish your stores early and often,” says Featherstun. “In general, however, you want to supplement for any activity lasting longer than 70 to 80 minutes.”

For runners looking to get the most out of their weekly long run, this is the starting point. The next consideration is how often they should replenish during their run or race.

“Current recommendations are to supplement every 20 to 30 minutes after that,” says Vogel. “But you need to incrementally increase in order to tolerate the added carbs.”

So while runners need to begin early and replenish often, they also need to practice timing, as well as formulation. Vogel suggests that runners begin with one gel per hour and practice that consistently before attempting to add more. “Much depends on the athlete and what their goals are,” she says. “But in general, you can try to increase by about 10-gram increments, week over week.”

With a wide range of carbohydrate products on the market, it’s also essential that runners try a variety to see what their GI systems prefer. “The biggest thing is figuring out which fuel you can take the most of,” says Featherstun. “You might love chews, but they can be harder to ingest than gels. Can you eat enough to meet your needs?”

Palatability matters, too. An athlete might love a berry flavored gel, but after four or five of them, do they start to struggle with the same taste? Helping runners understand the need for experimentation is key.

Sample and taste

Mike Cosentino, founder of Atlanta-based retailer Big Peach Running Co., says that his stores even offer samples to customers so that they can try multiple options.

“We also ask them question about pace, time of day they’re running and how long they’ll be out there,” he says. “Fueling needs are different for everyone, so the conversation we bring is critical. It allows our customers to have better results and gain confidence.”

For every runner, there’s a tipping point on how much carbohydrate they can tolerate, as well as how much actually gets converted to energy. In other words, more is not always more.

For retailers with a wide spectrum of runners – from the serious, high-end performers to the new, weekly social runner – there’s the ability to educate and help.

“We get inquiries every day about hydration and fueling and that bleeds over into general wellness, too,” says Cosentino. “This opens up opportunities for our brands and our business that we can capitalize on.”