How Training for a Half Ironman Challenged Everything I Thought I Knew About Nutrition

Every now and then, I start my run with an empty stomach. Sometimes I'm up before my stomach can even handle food, and I often dream about the breakfast that will revive me afterward. Or maybe I'm trying to shave off some calories by simply skipping a meal.

I know this is a harmful, diet-culture-adjacent line of thinking. But during training for a recent half Ironman Triathlon (which consists of a 1.2-mile swim, a 56-mile bike ride, and a 13.1-mile run), I had a nutrition reckoning that completely undid everything that diet culture had taught me about fueling my body.

Fresh off of a pelvic bone stress fracture, I knew that I needed to be intentional about meeting my nutritional needs. After all, research shows that nutrition can not only influence your performance during your training cycle, but it can also prevent stress fractures and hormone disruptions. In order to perform at my peak and stay injury-free, I'd need to focus on my nutrition — and let go of the pervasive diet rules that plague endurance athletes, such as avoiding entire food groups or trying to have a daily calorie deficit.

So before starting my training program, I decided to connect with a dietitian. Here's what I learned (and unlearned) about race nutrition and diet culture while training for a half Ironman.

Why Nutrition Is So Important for Triathlons

ICYDK, newbies and casual exercisers can expect to finish a half Ironman triathlon within five to seven hours. Over the course of those 70.3 miles, plus before and after the race, you need to be carb-loading, noshing on white bread, Pop-Tarts, pasta, and even pure glucose gels. These easily digestible sources of carbohydrates aren't always appetizing, but they provide the readily available energy you need to keep chugging along.

In fact, carbohydrates are the only macronutrient that can be broken down quickly enough to provide energy (in this case, in the form of glucose) during high-intensity exercise. And if you don't consume enough carbs to fully replenish your muscles' glycogen stores post-workout, your performance can take a hit — especially if you're tackling strenuous exercise regularly, according to research published in Nutrition Today. Regardless of the distance, "having adequate nutrition throughout the training cycle and on race day is one of the most important things an athlete should nail down," says Starla Garcia, a registered dietitian and elite runner.

The problem: Some athletes feel the need to stick with low-carb diets in hopes of reducing carbohydrate availability and training the muscles to more readily use fat for energy, according to the Nutrition Today research. Sure, this avoidance of carbs may be done in the name of improving performance — but it can also be viewed as a clear manifestation of diet culture, which posits that the nutrient leads to sugar crashes and "makes you gain weight," among other fatphobic ideas. And that couldn't be anything further from the truth.

The Diet Culture Myths I Busted While Training

As I prepped my body and mind for my half Ironman, I had to unlearn many of the diet culture myths that had been engrained into my mind over the years — and most of them were related to my previous association between weight loss and health, which is antithetical to the Health At Every Size movement.

Potential weight loss can entice people to triathlons or change their motivations, according to Debbie Newman Kassekert, a triathlon swim coach. "I often see athletes use their training to achieve weight loss," she explains. "While some healthy weight loss usually occurs with training, skipping snacks and meals will result in inadequate caloric and nutrient intake, which can greatly affect performance and recovery."

Here are three of the biggest eye-openers I had regarding nutrition, diet culture, and triathlon training.

Eating fewer calories isn't healthy — or sustainable.

Throughout my lifetime, I've had a habit of cutting corners to shave off a few pounds, meaning I'll skip the butter, scoop the center out of bagels, and avoid what's "bad" for me, even if that takes the fun out of food. Little did I know that doing so could have serious health consequences: Research finds that adequate caloric and calcium intake keeps you at peak bone mass and helps prevent broken bones. So my low-calorie diet may explain why I ended up with a pelvic stress fracture halfway through a marathon training cycle back in early 2022.

What's more, being in a calorie deficit zaps your energy and prevents proper recovery. Protein, carbohydrates, antioxidants, and sometimes dietary supplements show effectiveness in aiding in muscle recovery, research shows. If you're not consuming enough protein while sticking with a muscle-taxing exercise regimen, you could actually experience muscle tissue loss, according to the International Sports Sciences Association.

Athlete or not, underfueling may also increase your hunger levels to the point that you eat past the point of fullness, which can make you feel sluggish for the next day's workout. Training for a triathlon gave me permission to have a snack after breakfast or dinner, even if I had a solid meal. It made eating fun again, since fueling up allowed me more creative with my food choices.

'Healthy' food isn't always the right choice.

Instead of blindly reaching for what diet culture had taught me was the "healthy" choice (think: low-cal rice cakes), I had to start thinking strategically about what I ate and the timing of my meals. Because let's be honest: We all have the friend (or are the friend) who needs a bathroom break halfway through a run, thanks to a poorly timed stir fry or a fiber-heavy meal. Fiber is promoted for aiding in healthy digestion, but it's also linked with intestinal cramps and may promote the urge to poop (hi, runner's diarrhea), research shows. TL;DR: You don't want *active digestion* (i.e. potty breaks) when trying to complete a long run.

Before a long workout, Garcia suggests avoiding high-fiber foods that are promoted as "good for you," such as cauliflower or broccoli. This rule of thumb may save athletes from the tough-to-digest, number two-inducing fiber that also causes gastrointestinal discomfort during workouts. Simple carbs instead of whole grains are preferred, and rice, plantains, or tortillas are options as well.

After training or racing, athletes will need carbs (think: toast with bananas, quinoa bowls), along with muscle-rebuilding protein, to refuel, says Garcia. "A runner needs energy to...help them recover faster," and that energy comes via the sugars broken down from carbohydrates, she says. Specifically, eating carbs post-workout aids in recovery by helping to replenish your body's carbohydrate stores that were used up during exercise, as Shape previously reported. Skipping the refueling process is simply not an option.

You'll probably need more than plain water.

Novice triathletes like me often approach hydration the wrong way. "I usually start talking about hydration when I observe a fair number of clients showing up for a workout without a water bottle," explains Newman Kassekert.

But beyond forgetting a water bottle, many triathletes-in-training villainize sports drinks and the extra sugar and calories they provide. But that's not strategic for long endurance sports, says Garcia. ICYDK, electrolytes, including potassium and sodium, power your heart and prevent muscle cramps. Electrolytes provide electrical signals necessary for cells to function, as Shape previously reported. However, someone with a diet culture mindset might feel opposed to sports drinks in an attempt to avoid extra calories or carbs. (Gatorade Endurance Thirst Quencher, for example, contains 90 calories and 22 grams of carbs, 13 of which come from added sugars, per 12-ounce serving.) But while a calorie deficit may help you to lose weight, that's not the goal of training for an endurance race, and avoiding the calories in sports drinks won't lead to success in your sport. For athletes who are truly averse to sweet flavors, Garcia recommends lemon-flavored or plain electrolyte drinks.

The Takeaway on Nutrition, Diet Culture, and Triathlon Training

If you are unsure if you're fueling properly or if a diet culture mindset might be influencing your choices, consider hiring a triathlon coach or anti-diet nutritionist who can help guide you toward smart, strategic decisions in training. Not only that, but give yourself grace as you navigate this intentional change in eating and drinking. With race-day nutrition out of the way, all you'll be left to worry about is your ability to change a flat and if you can pee while sitting on a bike.