The Ideal Diet for Endurance Performance and Body Composition

As endurance athletes, we strive to strike the elusive equilibrium — the ideal blend of peak performance and optimal body composition. The conundrum that invariably arises is: can you shed weight while simultaneously boosting your performance?

A comprehensive study published in Sports Medicine in 2021 implies that the answer is more complex than we’d prefer.

The study, named “Effects of High-Fat Versus High-Carbohydrate Diets on Endurance Performance and Body Composition in Trained Athletes: A Systematic Review and Meta-Analysis”, scrutinized 23 studies comparing the effects of high-fat (HF) and high-carbohydrate (HC) diets on endurance performance and body composition in trained athletes.

So, what’s the final call? It appears that the diet you should embrace largely depends on your immediate goals.

High-Carbohydrate Diets: For Enhanced Performance: If you’re gearing up for an upcoming race or aiming to surpass your personal best in endurance events lasting longer than 60 minutes, a high-carbohydrate diet is your ally. The study revealed that HC diets led to better performance, providing the fuel your body needs to power through strenuous, prolonged workouts. During the season, when performance is paramount, focus on increasing your carbohydrate intake.

High-Fat Diets: For Improved Body Composition On the flip side, if your primary goal is losing weight and achieving a more desirable body composition, a high-fat diet might be the way to go. The reviewed studies showed that HF diets led to better body composition changes. However, it’s crucial to remember that a high-fat diet might not be conducive to peak performance, so you may need to set aside performance goals while focusing on weight loss. Off-season is the perfect time to shift your dietary emphasis towards increased protein and healthy fats. Here are some prevalent myths surrounding high-fat diets:

• Consuming fat triggers fat burning: True
• High fat diets lead to higher calorie burning: False
• A ketogenic state maximizes fat burning and offers a metabolic advantage: False
• Consuming more fat aids in losing more fat as you’re utilizing fat for fuel: False
• Carbohydrates are stored more readily than fat: False
• You consume less when your meals are high in fat: False
• Fat satiates more than carbohydrates: False
• Consuming fat before a meal reduces your subsequent intake: False

Research shows that people adhering to a specific diet, such as a high-fat one, often consume plenty of vegetables, meat, fish, eggs, fruits, nuts, and fats, while limiting starches, sugars, and processed foods. This balance aids in enhancing body composition. Similar to successful diets including: low-carb whole food (Whole 30), Paleo, Mediterranean, vegan, and gluten-free. While these diets can be challenging to maintain, they underscore the importance of nutrient-dense foods and a diet rich in vegetables, meat, fish, eggs, plant-based proteins, fruits, nuts, and fats, while restricting sugars and processed foods.

The Significance of Nutritional Timing

Beyond the type of diet, the timing of nutrition is pivotal in realizing your athletic goals. During the competitive season, when your training is intense and you’re participating in endurance events, your body requires instant energy — this is when you should increase your carbohydrate consumption. On the other hand, during the off-season, when your training intensity and volume is lower, it’s an ideal time to increase your protein and healthy fat intake to enhance body composition.

To sum up, the choice between a high-fat and a high-carbohydrate diet isn’t a matter of superiority. Rather, it hinges on your personal goals as an endurance athlete.

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Coach Joe Beckerley, CSCS
Triathlon Strong | Fuel The Finish

About: I am an expert in helping triathletes crush their next events! With over a decade of experience as a triathlon coach, I have helped hundreds of athletes with my knowledge and PR Playbook. I lead a life guided by my values and experience and have mastered the skills I coach others to develop. Together, we will ensure that you cross the finish line, Triathlon Strong!