Why would you want to be a fat adapted runner? Basically if you want endless and steady energy, able to dig deep when you need to? Never bonk or have blood sugar swings? If the answer is yes, then you want to be a fat adapted runner.
Fat adaptation is the process where bodies are trained to use our fat stores even when we are working at a higher intensity.
Our glycogen stores and carbohydrate fuel source are spared. This allows us to go faster with increased endurance for events.
Benefits of being a fat-adapted runner

For one thing, fat adaptation enables you to maintain higher levels of performance for longer periods, since your body can tap into a highly-efficient energy source that doesn’t require frequent refueling.
Even though fat-adaption is preferred by long distance runners and ultra runners, the performance benefits work for any runner.
Key Takeaway
Fat adaptation enables you to maintain higher levels of performance for longer.
Another added benefit is gut health. In ultra marathons, the number one reason for DNF’s is gut distress. Burning fat allows the athlete to take in far fewer carbs to get a performance boost. This saves the gut from shutting down.
Additionally, fat adaptation promotes metabolic efficiency and reduces the risk of developing chronic health conditions such as type 2 diabetes and cardiovascular disease.
11 Proven Tips To Become A Fat Adapted Runner
Whether you’re just starting out as a runner or are looking to take your performance to the next level, fat adaptation can help optimize your running experience.
Here are 11 proven tips to help you become fat adapted and reap all the benefits of this powerful metabolic state:
1. First Step – Deplete glycogen stores

In order to burn fat it needs to turn on fat-burning mode. This requires low carbohydrate availability.
When insulin drops, glucagon rises. The fastest way to do this is to adopt a lchf or fully ketogenic diet. This signals the body to burn fat.
This requires you to lower your carbohydrate intake. A low carbohydrate diet or ketogenic diet is essential to burn fat as your primary source of fuel.
The fat can come from fat stored (endogenous fat), or fat consumed (exogenous fat).
2. Avoid High-intensity Workouts at First

There is no need for speed as you start making the transition to becoming a fat-adapted runner. It’s important to limit stress and ease into this new way of training, especially if you’re coming from a background of consuming a high carbohydrate diet with high-intensity workouts.
Start with more moderate training sessions, such as easy runs and long-distance runs, to give your body time to adapt. Follow Dr. Maffetone’s Maximum Aerobic Function (MAF) heart rate zones.
3. Practice Intermittent Fasting.

Fasting is how to get fat adapted quickly. As a fat-adapted runner, one of the best ways to improve your performance and fat utilization is to experiment with intermittent fasting. Intermittent fasting, or IF, involves fasting for specific periods throughout the day – typically between 12 and 16 hours.
This allows your body to enter a fat-burning state that can help increase endurance and boost fat adaptation over time.
4. Use Fat Burning Supplements.

Ditching the carbs and becoming an efficient fat burner can be tough. Some supplements help with the process. Supplements can help with the sugar cravings
- MCT Oil or Powder
- Exogenous ketones
- Amino Acids or Amino Acid Peptides
- Electrolytes
- Vegetable broth, beef broth, or chicken broth
5. Keep the Fat Burning Fires Burning.
By warming up on an empty stomach, without carbohydrates, you force the body to use fat first. This prevents the blood sugar roller coaster that many atheltes experience.
To keep the body burning fat after workouts, wait until the body is fully cooled down before eating again. This can be as little as 15 minutes after you stop training.
If you are not hungry, there is no reason to consume any meal after training.
6. Experiment with different fat sources and macronutrient ratios.

Once you get over the initial phase where your body burns fat as its primary source of fuel, start experimenting with adding in carbohydrates. Finding what works best for your individual body and training needs can take some trial and error at first.
Include plenty of healthy fats in your diet. These include grass-fed ghee, lard, and tallow.
7. Good Sleep.

Getting enough quality sleep is essential for burning fat, the nervous system, and staying both physically and mentally healthy. So be sure to incorporate good sleep habits into your daily routine, including avoiding screens before bedtime and sticking to a regular sleep schedule as much as possible.
8. Eat Clean
To burn fat efficiently, ditch processed foods. Drink plenty of water and use electrolytes as needed. Add more water, electrolytes, or healthy fats if you crave sugar.
Excessive carbohydrate consumption is not the only contributor to inflammation. Seed oils, like those in salad dressings, can cause a great deal of inflammation as well.
9. Slow Down to Become Fast
The second part of the fat adapted running journey is training at a relatively low intensity. Dr. Maffetone’s Maximum Aerobic Function (MAF) heart rate training is essential to becoming a fat-adapted athlete.
10. Strategic Carbs
Once fat adapted, start tweaking your sports nutrition strategy. Don’t be afraid to consume carbohydrates or sports drinks during key workouts and on race day.
You won’t ruin your fat burning metabolism abilities as long as you add in strategic carbohydrates after the warm-up and before the cool-down.
As a long distance runner, the ability to burn fat, ketones, and carbohydrates will increase your energy levels and give you more energy on race day.
11. Stay focused and motivated
Becoming fat adapted as a runner is not something that happens overnight – it takes patience, Switching to a high-fat diet and depleting carbohydrate stores can be tough at first.
Take it easy and keep the consistency, and determination to reach your fat adaptation goals.
Questions & Answers
Can I lose body fat with a fat adapted diet?
You don’t need to train for an ultra marathon to use fat adaptation as a weight loss tool. Once the body converts to using fat as the primary fuel source it is easier to lose weight.
Incorporating ketogenic diets and intermittent fasting will help burn fat stores and contribute to lost weight.
Keep training levels to low to moderate intensity until you get to your ideal body weight.
What about Kenyan Runners?
Many factors contribute to fat-adapted running. Genetics, muscle fiber type, training volume, and intensity all play a role in how the body burns and utilizes fat.
Kenyan runners burn fat at a high level even though they have a high sugar intake and are consuming carbohydrates outside of training.
How long does it take to become fat adapted?
The process is different for everyone. As mentioned before, there are many factors involved. Genetics, training volume and intensity, sleep, and stress.
It can take as little as a week or two to burn more fat, burn through stored carbohydrate reserves, and have more energy. Or someone who is hypoglycemic or insulin resistant, it can take many months for more fat burning to take place.
The key is to go at your own pace and not compare yourself to anyone else. You are ultimately responsible for testing out what works best for you.
Do I need to be an ultra runner to benefit from fat adaptation?
Ultra running is a great sport and many elite runners use a fat-adapted approach to their fueling strategy.
Regardless of the distance, all runners can reap the benefits of using fat as fuel. The biggest reason is decreased chances of insulin resistance, diabetes, and heart disease.
How do I know I am fat adapted?
As a fat-adapted runner, it can be challenging to know if and when you have truly achieved fat adaptation.
However, some key signs can help you gauge your progress and determine whether you are burning more fat for fuel.
The key to knowing when you are fat-adapted is to pay attention to your body and the signs. These may include things like improved endurance levels, and you can “dig deep” where you feel like you have endless energy. Other indicators are reduced inflammation, faster recovery, better sleep, and more.
Need help with the Fat Adapted State?
Join my training group, or hire me as a coach. I will help you navigate your way to burning fat reserves, increasing your speed and endurance.
We cover topics like race fueling, base building, strategic carbs, and other lifestyle factors that will help you reach your goals.
Continued Reading
Check out the Nine Benefits of Running. If you haven’t started, you might want to start now.
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