Ketogenic diet for endurance athletes?

Ketogenic diet for endurance athletes?

A ketogenic diet is a diet where the body uses ketones as the primary source for fuel. There are many other names for a ketogenic diet. Other names are fat adapted, keto adapted, ketogenic diet, low carb diet, low carb high fat (LCHF).  Regardless of the name, the process is the same.  When the body produces ketones it is using fat as its fuel.

Benefits of a Ketogenic Diet for Endurance Athletes


Why should you try a ketogenic diet?  Because it makes an endurance athlete “bonk-proof”. This because of the amount of fat stores in the body.  Fat is almost an unlimited fuel source. Even the leanest athletes have over 80,000 calories stored. As opposed to glycogen stores, you can only store 1600-2000 calories in the body in the form of glycogen. Because bonking is due to running out of glycogen. When you are dependant on carbohydrates you can bonk.  When your body is running on fat, you cannot bonk.  Therefore, using fat as the primary source of fuel makes you “bonk proof”.

Happier Tummies

According to research, as many as 40% of endurance athletes complain of GI issues. Unanimous consensus would say that it sucks when this happens. Excessive carbohydrates upset homeostasis in the gut. Since athletes making ketones don’t use as much sugar, this keeps the tummy happy. This is especially true for longer events. GI issues felled many strong athletes. They spent the to much time in the porta potties and too little time on the course. It extreme cases they are not able to finish the race.

Train Harder

Finally, a ketogenic diet helps you train harder.  Some experts think it helps you recover better, but that is not the case.  You are able to train harder because there is less damage to the body during training.  Excessive glucose to the system causes damage because too much sugar is toxic to the body.  Therefore, if there is less damage, there is less need to recover.  This allows athletes following a ketogenic diet to bounce back quicker and train with higher intensities and harder.

How the Ketogenic Diet Works

Many endurance athletes consume a large amount of carbohydrates. When you eat something high in carbs, your body will produce use the carbohydrates in the form of glucose. Blood glucose is tightly regulated in the body. Normal blood sugar ranges are 79 to 110 mg/dL.
The body produces insulin to manage the carbohydrates in the blood stream. Glucose is the easiest molecule for your body to convert and use as energy. If you consume excessive carbohydrates, your body will use that energy first. To make ketones the body needs to go through its carbohydrates reserves.
After carbohydrate reserves become depleted the body starts to seek out alternative fuel sources. In absence of insulin in the blood stream signals the body to raise glucagon levels.  Glucagon sends a signal to tap into fat stores and to make ketones. If you continue to use Gu’s, sports drinks, and gels the body never depletes the glycogen stores. Because of this, your body doesn’t signal glucagon to rise. Over time, your body will lose the ability to burn fat. Hypoglycemia is the bodies inability to find an alternative fuel source.

Afraid of Ketones?

There is confusion in the medical community about ketosis and ketoacidosis. Ketosis is a normal metabolic state of low blood sugar and high ketones.  Ketoacidosis is a deadly state with high blood sugar and high ketones. As a result, this makes the body too acidic. This is deadly. The body has precise regulation of glucagon and insulin. This state is only possible for Type I diabetics and some Type II diabetics. Certain medications make Type II diabetics have ketoacidosis.
It is not possible for a non-diabetic to get can get ketoacidosis. As long blood sugar is low, a certain amount of ketones in the bloodstream is perfectly healthy.

What are Ketogenic Diet Macronutrient Ratios?

Ketogenic Diet Ratios
Typical Ketogenic Diet Ratios
The typical macronutrient ratios for a ketogenic diet are:
  • 60-75% of calories from fat (or even more)
  • 15-30% of calories from protein
  • 5-10% of calories from carbs. Usually less than  50 grams per day.



How Long Does It Take To Adapt?

It takes a while for the body to regulate its hormone production. Because the process of adaptation can take three to six months for the body to effectively use ketones for fuel. Furthermore, it takes about a year for the body to make fat its primary source of fuel. It may seem like a big commitment to change to a ketogenic diet. It is worth it long term. A ketogenic diet has as shown to be beneficial in many chronic ailments.The best part of the diet isn’t athletic performance. In addition to endurance performance, the diet has shown promising research in brain cancer, diabetes, Alzheimer’s and dementia. I rather like the idea of having the added benefit of keeping the brain and heart happy.

If you are like me, you probably want to spend more time geeking out on the subject.  Check out these additional resources to becoming a ketogenic athlete and fat burning machine.

Optimized Fat Metabolism by Peter Defty

Need Help Adapting?

Coach Stephanie:)
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Coach Stephanie

Hi, My name is Coach Stephanie Holbrook. I learned how to regain my health and turn back the clock. I now help endurance athletes show you everything you need to maximize health, performance and a younger feeling body.

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