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Race Fueling

Which Foods to Avoid at Aid Stations

Eat this. Not that.

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During a triathlon, aid stations can look like a lunchtime buffet with a smorgasbord of options for weary athletes: bananas, orange slices, chips, pretzels, cookies, fig bars, peanut butter and jelly, pickle juice, and even chicken soup. If you’re competing in an Ironman event, expect to see sponsor products too, like Gatorade Endurance, Red Bull, Maurten energy gels, and Quantum energy squares.

All of the aid station choices can be tempting—and confusing. But triathlon is far from a picnic, and just because something is at an aid station doesn’t mean you should necessarily eat it.

Recommendations for race-day fueling vary based on the individual athlete and on the intensity and duration of the event. Still, one cardinal rule reigns supreme: Nothing new on race day! Repeat after me: “I will not try any on-course nutrition that I haven’t trained with before.” Good. Now that’s settled, we can move into specifics.

RELATED: A Half-Ironman Nutrition Plan

The Race Nutrition Balancing Act

One of the most important aspects of race day nutrition is balancing the proportion and type of carbohydrates being ingested with fluid intake. If you’ve ever experienced a dreaded, sloshy stomach, then you know why this matters.

“Consuming a sports drink at 8% carb concentration, combined with chewable food, is risky as it may lead to dehydration and GI upset,” said triathlete Susan Kitchen, a registered dietician and board certified sports dietician, who helps athletes develop nutrition plans. “Ideally, a 4-6% carb concentration sports drink is better when mixed with chewables. The Gatorade at aid stations is 5.8%. Still, it’s a good idea to rinse chewables with sips of water to dilute and promote gastric emptying.”

“Fructose [sugar] is absorbed from the small intestine and transported to the liver, where about 50% is converted to glucose. Because fructose takes longer to absorb, it draws water into the gut to dilute, which can lead to gastrointestinal discomfort.”

Eat This: 4-6% carb sports drink with sips of water if taking in chewable food like an energy bar, fig bar, banana, or carb chews.

Not That: 8% or more carb concentration sports drink when mixed with chewable food. Be careful with fructose-only gels and chews. For example, Maurten energy gels have both fructose and glucose.

An athlete has gels stacked on his bike before the Ironman World Championships. Photo: Sean M. Haffey/Getty Images for IRONMAN

Train Your Gut

What you consume during a race also depends on the event’s duration. “Beyond not trying anything new on race day, the biggest mistake I see athletes make is over-fueling on race day (when they under-fueled in training) from fear of running out of energy,” Kitchen said.

Jessica Baxter, a triathlon and running coach and sports nutrition specialist, agrees with Kitchen that over-consumption of nutrition, especially “fast sugar” products, is a big mistake that can lead to GI distress. Other causes of tummy troubles include dehydration, high fat and high fiber foods too close to race day, too much caffeine, fructose, and NSAID (non-steroidal anti-inflammatory drugs) use.

“You may have seen bikes lined with dozens of gels and overstocked with highly concentrated sugar drinks,” Baxter said. “Athletes tend to fuel too much, occasionally, or by feel, rather than by a set schedule. The best way to race is to train with a detailed schedule of fueling. Test, adjust, and repeat until you find the right formula for you.”

On the other end of the spectrum, another big error is underestimating how much fluid and electrolytes are needed per hour.

“Many athletes are often surprised when they find out how much they should really be drinking,” Baxter said. She suggests using a two-pronged approach to dial in your fluid intake and sodium needs by doing a traditional sweat test and visiting a professional for sodium analysis.

So under-fueling is bad, but over-fueling might be even worse. How do you strike the right balance? Practice.

“It’s imperative that athletes train their gut just as they’re training their bodies for race duration and intensity in simulated training sessions, ideally for at least 4-6 weeks leading up to race day,” Kitchen says. “On race day, they will have test driven their fuel/hydration plan in various temperatures, humidity levels, durations, and intensities so they know exactly how to tweak the plan for race day conditions. I recommend writing down exactly what they ate and drank and how much they consumed after each training session. For the next session, they can refer back to their notes and omit what went poorly and repeat what went well.”

RELATED: How to Train Yourself to Drink

If what has been working in training doesn’t work in a race, think about how you’re taking it in.

“Frequent, small sips are better than chugging half a bottle every 30 minutes,” Kitchen said. “To promote gastric emptying, and avoid gastric shut down, sip early and often.”

“For every 25g of concentrated carbs, such as gels, bars, or chews, drink 12-16oz of water. This shouldn’t be taken in all at once. So, if you have test driven an energy gel or fig bar in training, then take little bites spread out over time (yes, even the gel) and sip water to wash it down. Try not to take the whole gel at once. Nibble on it over the course of a mile between aid stations and then toss in the trash and take water to rinse.”

Eat This: 12-16 oz. water with every 25g of concentrated carbs. For example, a Maurten energy gel has 25g carbs, a coconut almond chocolate chip Quantum energy square has 19g carbs, and four Gatorade Endurance carb energy chews have 31g carbs. A medium sized banana has 27g carbs.

Not That: Foods with high fat content like peanut butter or bars with nuts. Too much caffeine. NSAIDs close to race day.

Fueling on the Bike Versus the Run

While these are general principles, things get specific depending on which leg of the race you’re on. Due to factors like higher heart rate and increased dehydration risk, your fueling plan for the run should differ from the bike.

“On the bike, take in liquids and small bites of solids, evenly spaced out in the middle of the bike, not toward the end,” Kitchen said. “Wash this down with water. On the run, it’s better to stick with liquids, as bars, chips, pretzels, or cookies will increase GI disturbance. On the run, it’s risky to take any solids, and the hotter and more humid it is on race day the more you should avoid solids on the run.”

On both the bike and the run, Kitchen suggests avoiding food sources with fat, like peanut butter and bars with nuts, because fat slows gastric emptying. Caution should also be taken when consuming products with caffeine.

Baxter confirms that caffeine can increase gut motility, which can lead to loose bowels, diarrhea, and an unplanned T3 at the port-a-potty.

Kitchen recommends experimenting with caffeine in training to understand how your body reacts before implementing on race day. “Start with 1-2mg/kg of body weight,” she said. “Caffeine blood levels will peak 45-60 minutes after ingestion.”

Race intensity is another complicating factor when it comes to selecting aid station snacks. As a general rule, the higher the effort, the more basic your fuel plan should be.

“The athlete racing with their heart rate in Zone 4 should stick to liquids, as they need to keep digestion simple for the body,” Kitchen said. “The lower the effort, like an athlete racing with their heart rate in Zone 1 or 2, the more wiggle room there is to utilize options at aid stations. Still, by the time an athlete gets on the run, dehydration may have already set in. Keep that in mind and be sure to chase solids with cold water.”

On the Bike

Eat This: Sports drink and water. Energy gels or small bites of chewable food like a fig bar or banana, if desired.

On the Run

Eat This: Stick to liquid. Sports drink, water, gels, carb chews, or soup broth.

Not That: Stay away from solid food like bars, pretzels, cookies, chips.

RELATED: Are You Doing Thirst Right? The Science Says Probably Not

Consume primarily liquids on the run, and slow down if you experience GI distress. Photo: Andy Lyons/Getty Images

Fixing an Upset Stomach

Stomach distress, muscle fatigue, cramps, bloating, dizziness, and mental fogginess are all signs that a mistake has been made in your fueling plan. But don’t despair. Troubleshoot.

Kitchen said athletes should problem solve to uncover the source of GI distress. “Ask yourself questions like: Do I feel dehydrated? Am I still sweating? Is there white residue on my tri suit? Is my heart rate too high? Does my effort feel too hard for the distance I have left to travel?”

If you notice a white residue on your face and clothing, you’re a salty sweater. Be mindful of your sodium intake, especially during hot and humid days. If you’re feeling dehydrated, you’re probably sweating too much, not taking in enough fluid, or a combination of both. Stay ahead of fluid intake. If your stomach starts to feel upset or your heart rate gets too high, the first thing you should do is back off the intensity.

“If you start to feel a sloshy stomach, bloated, or cramping, slow down,” Kitchen said. “If you’re on the run, walk to get your heart rate down to allow blood to return to the gut from the working muscles to help facilitate digestion. The worst thing an athlete can do is take in more fuel, which will only exacerbate the problem.”

RELATED: The Science Behind How Stress Affects Your Gut Function

If you’re struggling to take in fuel, Baxter recommends using ice. “Put ice around your midsection to bring your core temperature down. This helps blood flow return to the stomach and digestion to speed up again. During this time, just sip on water. You can begin taking in carbohydrates once the stomach settles. Once the stomach has settled, take a carbohydrate source in small quantities to ensure your stomach doesn’t become upset again. Large quantities of sugar ingested all at once can lead to more stomach issues.”

If you still can’t decide what to select at an aid station, consider this final word from Baxter. “Think of your body as an engine. Products that aren’t necessarily good for you [i.e. junk food like cookies or chips] can potentially slow the engine down and your performance will suffer.”

Eat This: Salt, if you notice white residue on your face or clothing. Sports drink and/or water, if you’re feeling dehydrated.   

Not That: Junk food like cookies, chips, and pretzels.

Coke and Chicken Broth: Secret Weapons

There are a few secret weapons that have been known to revive even the weariest of triathletes.

“I’ve yet to work with an athlete who didn’t feel that Coke was a lifesaver on the run [during a long-course race],” Kitchen said. “It’s high in sugar, about 10% concentration, so it needs to be mixed with ice or followed up with a sip of water, but it hits the bloodstream quickly and will bring an athlete back to life energy-wise. Save Coke for your last trick. Make sure you’ve followed your fuel plan before you go to Coke. When you’ve exhausted all options, and still need a boost, that’s when you go to Coke. Once you go to Coke, you can only skip one aid station before you need to take a few more sips in order to keep your blood sugar up.”

In addition to a swig of flat soda, there’s another magical concoction: chicken broth. “This is liquid gold to some athletes when the sun goes down,” Baxter said. “If you’re depleted of electrolytes or calories, this is a nice treat to help boost those deficiencies.”

Eat This: Chicken broth to provide a boost of sodium. Coke, only if you’ve exhausted all other options, and only towards the end of the run.

Kitchen’s Basic Fueling Recommendations

Short-course (sprint or Olympic distance): 120-240 calories per hour, 30-60g carbs from simple sugar substrates, and no protein. 250-1,000 mg/hour of sodium (dependent upon an individual’s sweat loss).

Long-course (70.3 or full Ironman distance): 220-300+ calories per hour, 60-90g carbs per hour, 400-1,000+ mg/hour of sodium, and no protein. Carbs should come from multiple substrates. Avoid fructose-only sources.