Hidden Truths: Endurance Athlete Nutrition Misconceptions

Nutrition for endurance athletes is no longer a fringe topic—it’s central to peak performance. Yet, despite the growing interest, misinformation remains rampant. From carb-loading confusion to misguided fasted training, many athletes are making critical mistakes that compromise their performance, recovery, and long-term health.

In this article, we’ll break down seven common endurance nutrition myths—and explain the real science behind them. These insights come straight from a certified sports dietitian experienced in supporting endurance athletes at all levels.

Endurance Athlete Nutrition Misconceptions

1. Myth: Eating More Food Will Improve Performance

Some athletes believe that “carb-loading” or eating large meals before a race will give them an energy edge. Unfortunately, overfueling—especially right before an event—can backfire. It often leads to bloating, cramping, and stomach pain, particularly when unfamiliar foods or excessive fiber and carbohydrates are consumed.

Why it happens:
During exercise, blood flow is directed away from the gut and toward working muscles (de Oliveira et al., 2014). That makes digestion less efficient, increasing the risk of gastrointestinal distress.

Also, more carbs don’t always mean more fuel. A 2020 review found that once pre-exercise carbohydrates are consumed, the rate of carb metabolism during exercise doesn’t necessarily increase with higher intake (Rothschild et al., 2020). But skipping carbs altogether also leads to underperformance. Therefore, timing and moderation of meals are important.

Key takeaway:
Eat foods your body tolerates well. Focus on easy-to-digest carbs before the race—and test your fueling strategy during training, not on race day.

2. Myth: Fast-Digesting Carbs Are Always Better During Exercise

It’s a popular belief that “fast” carbs like glucose are superior for energy during long events. But this is too simplistic.

Here’s the real story: your body can only absorb about 60 grams of a single type of sugar per hour (Jeukendrup, 2014). But combining different sugars—like glucose and fructose—allows the body to use up to 90 grams per hour or more.

Example:
In one study, a mix of glucose and fructose increased carbohydrate oxidation by 75% compared to glucose alone (Currell & Jeukendrup, 2008).

What this means for you:

• For short events (<2 hours), a single sugar source is often enough.
• For longer events, use products with multiple transportable carbohydrates (e.g., glucose + fructose or maltodextrin + fructose) for better energy and digestion.

3. Myth: It Doesn’t Matter How You Get Your Calories

Some athletes think that as long as they hit their calorie or macronutrient goals, the form—solid food vs. liquid—doesn’t matter. But this isn’t true, especially during endurance events.

Why it matters:

• Solid foods require more digestion, which can be problematic during high-impact activities like running.
• Liquid nutrition (like gels or drink mixes) is absorbed faster and causes fewer stomach issues, especially during long races.

Tips:

• Cyclists: You may tolerate solid options like energy bars or rice cakes.
• Runners/Triathletes: Stick to fluids or gels paired with water for easier digestion.

4. Myth: Fats Don’t Help with Performance

Many endurance athletes avoid fats entirely, thinking they’re slow to digest and won’t support energy needs. But this is only partially true.

Here’s the nuance:
Yes, fats are slower to digest, so you shouldn’t eat a high-fat meal right before a race. But during longer, lower-intensity efforts, your body relies heavily on fat metabolism for fuel—especially if you’re well-trained.

Fun fact:
Elite endurance athletes often burn more fat and preserve glycogen during exercise. If your diet is too carb-heavy and low in fats, your performance may plateau.

Suggestions:

• Add healthy fats (like nuts, seeds, and fatty fish) to daily meals.
• Avoid high-fat meals right before training or racing.

5. Myth: If It Works for Them, It’ll Work for Me

Copying someone else’s nutrition plan—whether it’s your training partner or a pro athlete—is risky.

Why?
Everyone has different energy needs, digestion speeds, sweat rates, and metabolic responses.

Example:
If an amateur cyclist tries to match a pro’s intake—say 100g of carbs/hour and 1L of water—they may feel bloated or sluggish. High-carb intake without proper adaptation can overwhelm your gut.

Best practice:
Start with general guidelines (e.g., 30–60g carbs/hour) and adjust based on your training data, body weight, and personal tolerance.

6. Myth: I Should Constantly Drink Water During Exercise

Overhydration can be just as dangerous as dehydration.

During prolonged endurance events, your body loses both fluid and electrolytes (sodium, potassium, chloride). Replacing only water can lead to hyponatremia, a potentially life-threatening condition caused by low blood sodium.

What to do instead:

• Use electrolyte mixes or sports drinks, especially in long events or hot weather.
• Measure your sweat rate to personalize your fluid intake:

Formula:
(Pre-exercise weight – post-exercise weight + fluid consumed – urine volume) ÷ hours exercised = sweat rate (L/hr)

Extra tip:
Drinking cold fluids in hot environments can help lower core body temperature.

7. Myth: Training Fasted Helps Burn More Fat

“Train low” (with low carb availability) is a trendy tactic, but it comes with risks—especially for endurance athletes.

Problem:
Endurance training is catabolic. If you don’t consume adequate carbs or protein, your body may start breaking down muscle tissue for energy (Tarnopolsky, 2004).

Solution:
Fuel your sessions with carbs and a bit of protein to protect muscle and support recovery. For long workouts, intra-session protein (like BCAAs or small protein-carb combos) can help reduce muscle breakdown.

Caution:
Fasted training can be effective when used selectively and in the right training phase—but should not be your default approach.

Conclusion: Personalization Beats Popularity

Understanding the truth about endurance nutrition requires more than following trends. It means recognizing your body’s unique needs and adjusting accordingly. The right strategy is personalized, evidence-based, and tested in training—not on race day.

If you want help optimizing your endurance nutrition, reach out for a personalized consultation with our sports dietitian. Whether online or in-person, we can help you fuel smarter and perform better.

References

• Tarnopolsky, M. (2004). Protein requirements for endurance athletes. Nutrition, 20(7–8), 662–668. https://doi.org/10.1016/j.nut.2004.04.008
• Currell, K., & Jeukendrup, A. E. (2008). Superior endurance performance with ingestion of multiple transportable carbohydrates. Medicine & Science in Sports & Exercise, 40(2), 275–281. https://doi.org/10.1249/mss.0b013e31815adf19
• Jeukendrup, A. (2014). A step towards personalized sports nutrition: carbohydrate intake during exercise. Sports Medicine, 44 (Suppl 1), S25–S33. https://doi.org/10.1007/s40279-014-0148-z
• de Oliveira, E. P., Burini, R. C., & Jeukendrup, A. (2014). Gastrointestinal complaints during exercise: prevalence, etiology, and nutritional recommendations. Sports Medicine, 44(Suppl 1), S79–S85. https://doi.org/10.1007/s40279-014-0153-2
• Rothschild, J. A., Kilding, A. E., & Plews, D. J. (2020). What Should I Eat before Exercise? Nutrients, 12(11), 3473. https://doi.org/10.3390/nu12113473