The Most Common Triathlon Nutrition Mistakes (You Don't Know You're Making)
I’m guilty of making some of the most common triathlon nutrition mistakes.
But the thing is, I thought I was doing it right. I wasn’t one of those athletes who didn’t think about their nutrition strategy until race week.
I tested my nutrition for months in training
I went into the race with a specific plan
I executed the plan to the letter
But even then, I still suffered from problems like dizziness, energy drain, and nausea. I’ve walked/hobbled to the finish line of an Olympic, because I could barely stand upright and had stars in front of my eyes. I vomited from mile 9 to 20 of the marathon at the end of an IRONMAN.
Sound like fun? It’s not.
Nutrition problems can make you feel like all of your training was a waste, like the hours and days and months you spent working and sacrificing and fine-tuning didn’t even matter. It’s the kind of thing that can cause athletes to leave the sport entirely.
And I was sick of it (literally). So I started working with a sports nutritionist.
Turns out, I was doing a few things wrong:
I didn’t understand that all carbohydrate sources aren’t created equal
I underestimated the importance of doing even short runs with nutrition
I wasn’t doing a great job with my pre and post-workout nutrition
My pacing was off, which was affecting digestion and absorption
I want to help other athletes who suffer from similar issues. In an upcoming article for IRONMAN- Endurance Nutrition Basics 101: How to Fuel For a 70.3 Triathlon, I interviewed my own sports nutritionist to help demystify and simplify triathlon nutrition. (To be published soon)
But this is a complex topic, so in today’s newsletter you’re getting all the extra bits that I couldn’t fit into the article! We’ll talk about the ideal carb/sodium/fluid ratios, how your body absorbs fuel during exercise, and why you can’t just eat gummy bearsand hope for the best.
For paid subscribers, we’ll talk about the most common nutrition mistakes triathletes make, and I’ll share some of the big changes I’ve made to my own fueling plan. Also, we’ll break down the most common race day nutrition problems and what to do in the moment to salvage your race.
If you’re a triathlete training for a 70.3, Ironman, or even a runner prepping for a marathon, this post will help you avoid the biggest nutrition pitfalls we make as endurance athletes.
I’ve said this before, and I will say it again. Nutrition is not one-size-fits-all.
There are many factors that affect how much you should eat and drink during training and on race day. Some of these might seem obvious, and some may surprise you.
Length and intensity of a workout or race
Gut tolerance
Sweat rate and sodium loss (weather component)
Fitness level
Racing experience
Energy expenditure
This means your nutrition strategy for a sprint triathlon is going to be different than for an IRONMAN. It means your nutrition plan may change based on weather conditions. It means you might not be able to take in the same amount of carbohydrates and fluid as the athlete standing next to you on the start line.
And that’s ok. You just have to find out what works best for you (with the help of best practices and guidelines based on actual science, not social media).
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No, You Can't Just Eat Gummy Bears and Hope For the Best.
While your favorite Instagram influencer might say you can fuel for an Ironman solely with Nerd gummy clusters, that’s just not reality. (Pssst. They just want more clicks on their video.) I mean you can try it. But given that the first ingredient is corn syrup, not to mention the binders used like gelatin and carnauba wax, and the sheer quantity you’d have to ingest, let me know how your stomach responds to that during the second half of the marathon…
As an athlete in the modern age, we’re inundated by an overwhelming amount of information, and it can be hard to separate fact from fiction.
That’s why I seek advice from experts.
Today’s expert: Marni Sumbal, Board Certified Sports Dietician and owner of TriMarni Coaching and Nutrition
For endurance athletes, the most likely contributors of fatigue are dehydration and glycogen (carbohydrates) depletion, Marni says.
The trick is figuring out how much to drink and eat. Think like Goldilocks. Too little and you risk bonking and not having enough energy to make it to the finish line. Too much and you can face stomach upset, nausea, or diarrhea.
The goal is to come up with a fueling strategy that supports your body through training and on race day so you can perform to your potential. Let’s consider a 70.3 triathlon as an example.
The three main components to think about are carbohydrates, fluid, and electrolytes (sodium).
“A good starting point per hour is 60-70g carbs, 400-600mg sodium, and 24-28 ounces of fluid. If you’re new to using sport nutrition or have a sensitive stomach, start off with 40-50g/hr carbs and gradually work your way up,” she says.
And yes, research has shown that endurance athletes can consume up to 90-100g carbs per hour, but Marni says it’s not necessary for most athletes. That’s because your fueling strategy is impacted by your energy expenditure.
If you’re able to exercise at a high intensity, for long periods of time, then you need to replace the fuel you’re burning. On the other hand, if you aren’t operating at a high intensity, but still taking in the max amount of carbs, you risk overwhelming your stomach, which can lead to GI distress.
The Problem with Eating and Drinking During Exercise
The amount of nutrition we take in is key, but how we consume it is equally as important. The best advice I received was to think about nutrition like having an IV drip. Don’t try to drink half a bottle at one time. Take small sips every 10-15 minutes to help with digestion and absorption, Marni says.
This applies to energy gels and salt tabs as well. It’s not the best idea to dump 30g carbs or 200-400mg sodium into a stomach that’s already compromised due to heat, dehydration, and intense exercise. That’s how GI upset can happen.
Instead of gulping an entire gel at once, take half, wait 10-15 minutes, then take the other half. If you must take salt tabs, be sure to space them out as well.
The unfortunate truth is that our digestion is compromised during exercise. This is because exercise shifts blood flow away from the GI tract towards our heart, lungs, and muscles. In order to make sure carbohydrates are being emptied from the stomach in this state, we need easily digestible carbs.
But all carbs aren’t created equal. There’s glucose, maltodextrin, fructose, and sucrose, and they all have their own unique personalities.
After the carbs are digested, they get absorbed. But there’s a catch. They need help from a little guy called a (transporter protein) to get across the intestinal wall. Marni explains there are two transporter proteins that help carbs make this difficult journey. They’re called SGLT1 and GLUT5.
Why is this important?
If your sports drink has glucose, sucrose, galactose, maltodextrin, or starch, the SGLT1 gets saturated at 60g carbs per hour. He’s overwhelmed and exhausted. That means even if you take in more carbs, he can’t help you process them.
As a result, the excess carbs accumulate in the intestines, and your muscles will continue to fatigue, despite taking in a large amount of carbs. That dramatically increases the risk for GI upset, Marni says.
“If you’re simply consuming carbohydrates without awareness of how much you’re consuming, what types of carbs you’re consuming, and how often you’re consuming them, there's a good chance you aren’t optimizing absorption, which means a greater risk for bonking, early fatigue, dehydration, and GI issues,” she says.
Luckily, there’s a trick to getting around this with glucose’s friend called fructose.
Fructose uses the other transporter, GLUT5. He steps up when SGLT1 is too tired to go on. That’s why nutrition companies will use fructose, in addition to glucose or maltodextrin, to allow athletes to take in more carbohydrates per hour.
Research shows the ideal combination of carbs includes:
maltodextrin : fructose
glucose : fructose
glucose : sucrose : fructose
Bottom Line: If you want to consume more than 60 grams of carbohydrates per hour, you need a product with multiple carbohydrate sources.
“To increase the capacity to absorb carbohydrates, it's critical that your sports drink has the right formulation,” Marni says. “Simply eating and drinking whatever you want, whenever you want, doesn’t guarantee that what you’re consuming is being digested and absorbed.”
We can’t conclude this section without talking about electrolytes. We lose electrolytes like sodium when we exercise, and it’s important to replace both fluid and electrolytes to prevent dehydration…