Coach Debbie Potts and coach Stephanie Holbrook discussed, “Should You do keto for endurance training”?

As trained endurance athletes, coaches and athletes with a combined 40-plus of experience, we delve into our insights on implementing a ketogenic diet for endurance training during that period.


Too Long: Didn’t Read

A ketogenic diet can be an effective way to boost fat oxidation in the short run. However, a more nuanced approach for a long-term strategy is needed to improve health, longevity, and sports performance.

Since we are all unique individuals, we must experiment and find what works best for each of us. Consuming real, high-quality, nutrient-rich foods is crucial regardless of your nutrition plan.

Should you do Keto for Endurance Training Discussion?

Coaches Debbie Potts and Stephanie Holbrook discuss Keto for Endurance Training.

Are you an elite endurance sport athlete considering a switch to the ketogenic diet?

With its emphasis on higher-fat, low-carb foods, the keto diet has gained popularity recently as a weight loss and health improvement tool.

However, as athletes and coaches, we discuss the nuances of adopting the keto diet for endurance training.

Understanding Keto Diet

Definition of Ketosis

Ketosis is when your body burns fat for fuel instead of carbohydrates. This occurs when you follow a high-fat, low-carbohydrate diet, such as the ketogenic diet.

By reducing your carbohydrate intake, your body switches to utilizing stored fat for energy. Consequently, the liver generates ketones, serving as an alternate fuel source for the body.

Macronutrient Ratios

The ketogenic diet, characterized by its low carbohydrate, high-fat diet (LCHF) macronutrient ratio, typically involves consuming 70-75% of daily calories from fat, 20-25% from protein, and 5-10% from carbohydrates.

This macronutrient ratio is designed to keep your body in ketosis, emphasizing the role of the LCHF diet in maintaining this metabolic state. However, it’s important to note that the exact macronutrient ratios may vary depending on your needs and goals.

Keto Adaptation Process

When you first start the ketogenic diet, your body may undergo a period of adjustment known as the keto adaptation process. Your body switches from using carbohydrates as its primary fuel source to using fat and ketones.

This process can take anywhere from a few days to a few months. As an athlete, it is best to adapt to the diet when you are in the correct training phase.

The Transition and Base training phases are the best times to adapt to keto if you have been following a high-carbohydrate diet.

Burning fat as your primary fuel source can help you lose weight and improve your health. But it can also cause problems with your health and even impair exercise performance if you go to extremes and add too much stress to your diet.

Debbie and I have the experience to help you adapt to burning fat as your primary fuel source.

Benefits of Keto in Endurance Training

Enhanced Fat Oxidation

One of the main benefits of following a ketogenic diet for endurance training is enhanced fat oxidation. When restricting carbohydrate intake, your body uses fat as its primary fuel source.

This adaptation not only increases fat-burning capabilities but also leads to a significant reduction in body fat, which is particularly beneficial during moderate-intensity exercise.

This means that during exercise, especially moderate-intensity exercise, your body can burn more fat for energy.

This shift helps maintain energy levels over a longer period and positively affects body composition by decreasing body fatness.

This is crucial for athletes aiming to improve their own endurance endurance exercise capacity, and performance while optimizing their body composition for better health and athletic output.

Glycogen Sparing Effect

Another benefit of following a ketogenic diet for endurance training is the glycogen-sparing effect. When you restrict your carbohydrate intake, your body uses up its glycogen stores more slowly.

This means that you can maintain your energy levels for longer periods, which can be especially beneficial during longer endurance events.

Weight Management

Following a ketogenic diet can also be beneficial for weight management. When you restrict your carbohydrate intake, your body will naturally start to burn more fat for energy. This shift not only helps in reducing body weight but also leads to significant changes in body composition, including a decrease in body fat and an increase in lean body mass. Such changes are particularly advantageous for endurance athletes, as they contribute to improved race performance, lower perceived exertion, and potentially enhanced VO2 max by optimizing substrate, fat utilization, and metabolism.

This can help you lose weight and maintain a healthy body composition, which can be especially important for endurance athletes who need a lean physique.

Overall, following a ketogenic diet for endurance training has several benefits, including enhanced fat oxidation, muscle glycogen- sparing, weight management, and favorable alterations in body weight and composition.

However, this type of diet is not optimal if you have not built a large fitness base and are doing high-intensity interval training (HIIT). Having a large training volume combined with intermittent fasting is not optimal.

It is always important to consult with a healthcare professional before significantly changing your diet or exercise routine.

Challenges of Keto for Endurance Athletes

Regarding endurance training, following a keto diet can present challenges that may affect your performance. Here are some of the most common challenges you may face:

Transitioning to a higher carbohydrate intake and high-fat diet can initially challenge elite athletes as their bodies adapt to utilizing fat over carbohydrates for fuel. Still, this shift can lead to significant performance benefits, including improved fat oxidation, metabolism, and endurance. Despite the initial dip, proper adaptation and strategic dietary planning, such as periodized nutrition and ‘training low’ practices, can improve exercise performance over time by enhancing fat metabolism, sparing glycogen stores, and promoting high-intensity race performance.

Understanding the unique responses of elite athletes to ketogenic diets is crucial, emphasizing the need for personalized dietary strategies to optimize performance and fuel utilization.

Initial Performance Dip

One of the most significant challenges of following a keto diet for endurance athletes is the initial dip in performance that many experience.

Your body needs time to adapt to using fat as its primary fuel source instead of carbohydrates.

During this adaptation period, you may feel sluggish, be unable to sustain high-intensity efforts and experience a decline in overall performance.

Electrolyte Imbalance

Another challenge of following a keto diet for endurance training is the potential for electrolyte imbalances.

When you restrict carbohydrates, your body produces less insulin, which can cause a decrease in electrolyte absorption.

This can lead to imbalances in sodium, potassium, and magnesium, which can cause cramping, fatigue, and other performance issues.

Using All the Fuel Sources

A ketogenic diet is great for increasing fat oxidation rates and training your body to burn fat as its primary fuel source. However, it isn’t so great for reaching your peak performance.

Once you become well fat-adapted, it is time to add back in some carbohydrates to improve performance.

Strategic carbs allow you to dig deep and increase your speed and pace. For instance, elite race walkers have successfully utilized strategic carbohydrate intake within a ketogenic diet framework to enhance their performance, showcasing the potential benefits of this approach in high-endurance sports. Strategic carbohydrates are strategically added to an athlete’s diet during key workouts, harder training sessions, and/or races to improve performance specifically.

Definition of Strategic Carbohydrates:

Carbohydrates are added to key workouts, harder training sessions, and/or races to improve performance.

While following a keto diet for endurance training may have some benefits, it’s important to be aware of the challenges it presents. By understanding these challenges and taking steps to mitigate them, you can optimize your performance and achieve your training goals.

Adapting Keto to Endurance Training

If you are considering adopting a ketogenic diet for endurance training, it is important to understand how to adapt your diet to ensure optimal performance. Here are some key strategies to consider:

A high fat diet can be pivotal in periodizing carbohydrate intake for endurance training, allowing athletes to maximize their metabolic efficiency and fuel utilization during long-duration activities.

It’s also crucial to tailor hydration and electrolyte management strategies to meet the specific dietary needs of male endurance athletes, ensuring they maintain peak performance and recovery throughout their training regimen.

Periodization of Carbohydrate Intake

While a strict ketogenic diet involves consuming very low levels of carbohydrates, some athletes may benefit from incorporating targeted carbohydrate intake around their workouts.

This can help provide the necessary energy for high-intensity training sessions while maintaining the benefits of a ketogenic diet during rest periods.

Supplemental Strategies

In addition to adjusting carbohydrate intake, some athletes may benefit from incorporating supplements to support their training.

Amino acids are the building blocks of protein, and they play an important role in endurance training.

Creatine, for example, has been shown to improve performance during high-intensity exercise, while beta-alanine can help delay fatigue.

Electrolyte supplements can also be useful for maintaining proper hydration and electrolyte balance.

Fats and bomb fuels can be used as energy.

Carbohydrates are still an important fuel with endurance performance when used correctly.

Hydration and Electrolyte Management

One potential drawback of a ketogenic diet is the risk of dehydration and electrolyte imbalances. To avoid this, it is important to prioritize hydration and electrolyte management.

This may involve consuming electrolyte-rich foods like leafy greens and avocados and supplementing with electrolyte drinks or powders.

Adapting a ketogenic diet to endurance training requires careful planning and consideration.

By adjusting carbohydrate intake, incorporating supplements, and prioritizing hydration and electrolyte management, you can optimize your performance while reaping the benefits of a ketogenic diet.

Scientific Research on Keto and Endurance

Studies on Long-Term Effects

Several studies have been conducted to determine the long-term effects of a high-fat, low-carb diet on endurance athletes.

The FASTER Study showed that athletes significantly increased fat oxidation during exercise after six months of following a ketogenic diet.

Jeff Volek and the FASTER STUDY. Keto for Endurance

This suggests that the body becomes more efficient at burning fat for fuel, which can benefit endurance athletes who need to conserve glycogen stores.

Endurance Performance N = 1

In every study, Coach Debbie and Coach Stephanie advocate discovering what suits you best. Dr. Daniel Plews, a top-tier athlete and coach, embodies the art of fine-tuning and personalizing your nutrition to achieve outstanding endurance sports results.

Dr. Dan Plews employed this method to win the 2018 Ironman Age Group World Championship, setting a record with a winning time of 8 hours, 24 minutes, and 36 seconds.

Dr Daniel Pews on his Right Fuel at the Right Time approach.

Personalizing the High-Fat Diet

If you’re considering a ketogenic, low-carbohydrate, high-carbohydrate, high-fat diet for endurance training, it’s important to personalize the diet to meet your individual needs. Here are some key factors to consider when personalizing the keto diet for athletes:

Individual Energy Needs

Everyone’s energy needs differ, and athletes have higher energy needs than sedentary individuals.

When following the keto diet, it’s important to ensure you consume enough calories to meet your energy needs.

This may require increasing your healthy fats and protein intake to ensure you get enough fuel for your workouts. It’s also important to listen to your body and adjust your energy intake accordingly.

Training Demands

The intensity and duration of your workouts will also play a role in personalizing the keto diet for athletes.

High-intensity, short-duration training may not require as many carbohydrates as longer, endurance-based workouts. However, if you’re training at a high intensity for extended periods, it may be beneficial to increase your carb intake slightly to support improved performance.

Consulting with a registered dietitian specializing in sports nutrition can help you determine the best approach to meeting your energy needs while following the keto diet.

Timing is Key

Another key factor to consider when personalizing the keto diet for athletes is timing. Consuming carbs before or during intense workouts can provide

Training Intensity and Volume

The intensity and volume of your training can also impact your keto diet needs. Endurance athletes may require more carbohydrates to fuel their workouts, while athletes engaging in lower-intensity exercise may be able to get by with fewer carbs.

Experimenting with your carbohydrate intake to find the right balance for your training needs is important.

Recovery and Nutrition Timing

Nutrition timing is also important for athletes, especially regarding recovery. Consuming protein and carbohydrates after a workout can help to replenish glycogen stores and promote muscle recovery.

When following the keto diet, it’s important to ensure you’re getting enough protein and to time your meals appropriately to support your training and recovery needs.

Overall, personalizing the keto diet for athletes requires careful consideration of individual energy needs, training intensity and volume, and recovery and nutrition timing.

By experimenting with your diet and paying attention to your body’s needs, you can find the right balance of macronutrients to support your athletic performance and overall health.

Keto Diet Variations

If you’re considering a ketogenic diet for endurance training, you may hear about some different terms related to using strategic carbs in your training.

Don’t be fooled; all approaches are the same, with some nuances. Each approach aims to guide you using strategic carbohydrates to help you become a fat-adapted athlete and perform well.

The classic keto diet involves consuming high fat, moderate protein, and low carbohydrates. Typically, this means consuming around 75% of calories from fat, 20% from protein, and only 5% from carbohydrates.

Another popular variation is the targeted ketogenic diet (TKD), which allows for a higher carb intake around intense training sessions to provide quick energy for performance. This approach still maintains a low carb intake overall but strategically adds carbs when needed.

The cyclical ketogenic diet (CKD) involves cycling between periods of strict keto and higher-carb days. This can be useful for athletes with particularly high training volume or intensity, as it allows for more glycogen replenishment without sacrificing the benefits of ketosis during certain periods.


Targeted Ketogenic Diet (TKD)

The targeted ketogenic diet (TKD) involves consuming a small amount of carbohydrates before or after exercise to provide your body with the energy it needs for high-intensity workouts.

This can help you perform better during workouts and recover quickly afterward. To follow a TKD, you’ll need to carefully time your carbohydrate intake and ensure you’re eating the right carbs.

Cyclical Ketogenic Diet (CKD)

The cyclical ketogenic diet (CKD) involves cycling between periods of strict keto dieting and higher-carb eating.

This can be a good option for athletes who want to build muscle mass while maintaining the benefits of a ketogenic diet. During the high-carb periods, you must choose healthy, nutrient-dense foods that won’t derail your progress.

High-Protein Ketogenic Diet

The high-protein ketogenic diet is similar to the standard ketogenic diet, but with a higher protein and fat intake amount.

This can be a good option for athletes who are looking to build muscle mass and maintain their energy levels during workouts.

However, it’s important to remember not to worry about being “kicked out of ketosis”.

No matter which type of ketogenic diet you choose, working with a qualified professional is important to ensure you get all the nutrients in the right ratio for your body to perform at its best.

Following the right guidelines and making smart choices, you can use a ketogenic diet to fuel your endurance training and achieve your fitness goals.

Practical Tips for Endurance Athletes on Keto

Meal Planning

Meal planning is crucial when following a ketogenic diet for endurance training. You must consume enough calories to fuel your workouts and maintain your energy levels.

You should focus on consuming healthy fats, such as lard, tallow, and coconut oil, and protein from food, lamb, game meat, eggs, fish, and poultry.

To ensure that you meet your nutritional needs, consider consulting with an experienced coach who can help you create a meal plan that meets your needs.

Additionally, you may find it helpful to track your food intake using an app or journal to ensure you get the right balance of macronutrients.

Monitoring Ketone Levels

Monitoring your ketone levels can help you determine whether you are in ketosis and whether your diet supports your endurance training goals. Several ways to monitor your ketone levels include urine strips, blood tests, and breath tests.

This is important when first adopting the diet, but it becomes less important as you continue to adapt to training.

Urine strips are the most affordable option but may not provide the most accurate results. Blood tests are more accurate but can be expensive and require a finger prick.

Breath tests are non-invasive and provide quick results, but they may not be as accurate as blood tests.

Adjusting to Training Demands

As you adjust to a ketogenic diet, it is important to pay attention to changes in your body composition and your endurance exercise performance. Initially, you may experience a decrease in energy levels and performance, but this should improve as your body adapts to using ketones for fuel.

Limit your stress by following a low heart rate approach, like MAF Training, to training until you feel your energy is returning.

Focusing on meal planning, monitoring your ketone levels, and adjusting your training to meet your body’s needs can set you up for success.

Potential Risks and How to Mitigate Them

Nutrient Deficiencies

There is a risk of deficiencies when following a keto diet. Because hunger is lessened, ensure you get enough fuel to maintain lean mass and energy levels.

To mitigate this risk, consuming various nutrient-dense foods such as red meat, eggs, and occasionally organ meats will mitigate this potential problem.

It is also important to monitor your nutrient intake and consult a healthcare professional if you have concerns.

Long-Term Health Considerations

The short-term benefits of a keto diet have been shown to improve many people’s health and body composition responses.

A long-term approach must consider your long-term endurance performance, training, and racing goals. To mitigate this risk, monitor your overall health and how you look, feel, and perform.

If you have concerns, contact a keto-focused healthcare professional. Good resources are Ketogenic and Diet Doctor.

It is also important to ensure that you consume various healthy fats, such as those found in grass-fed tallow, pasture-raised lard, butter, ghee, and coconut oil. Avoid all trans fats and seed oils.


In summary, the effectiveness of a high-fat keto diet for endurance training must be customized to each individual’s needs. There is no one-size-fits-all.

Always listen to your body and go by how you look, feel, and perform. Don’t be intimidated by experimenting with different fuels to discover what works for you. Make adjustments as necessary.

Coach Debbie and Coach Stephanie are here to help you succeed with your endurance training goals. They have both utilized the keto diet in their own training and have seen significant improvements in performance. With the right guidance and support, you too can reach your full potential on a high-fat keto diet.

Remember to incorporate strength training into your routine to improve overall muscle function improve exercise performance, and prevent injury. Also, prioritize rest and recovery for optimal performance.

Finally, do not underestimate the power of mindset. Stay positive and believe in yourself – with determination and consistency, you can achieve anything you set your mind to.

So go ahead, give it a try! Fuel your body with healthy fats and reap the benefits of improved endurance, weight management, mental clarity, and overall health. Trust us, your body will thank you. And if you need any help along the way, don’t hesitate to reach out for support and guidance. Happy keto-ing!

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