Photo by Tom Sharrow/

The ketogenic is a classic example of a low-carb diet.  In many low-carb diets, people will consume a small amount of carbs (20%) and protein (30%) with about half their diet being fats.1  In a ketogenic diet, people will consume fats for three-quarters of their diet, carbs for around 5% of their diet and protein will comprise approximately 20% of their diet.  With this diet, the body switches its metabolism to being more efficient in using fat as a fuel.  As fat is metabolized and carbs decrease, ketones are produced in the liver by using fatty acids.  Ketones can be used to provide energy without the presence of carbs during long periods of exercise.  This information can be useful to athletes in endurance sports.

Endurance Athletes on a Keto Diet

According to a study by Volek et al. in “Metabolic characteristics of keto-adapted ultra-endurance runners,” many athletes have been successful in switching to a low-carb diet from a high-carb one.2  In this study, twenty top ultra-marathoners and Ironman distance triathletes were tested for performance under conditions of both high-carb and low-carb diets.  Those who consumed fewer carbohydrates experienced long-term keto-adaptation and burned about 2.3 times more fat than those who consumed more carbohydrates in a 3-hour exercise session.

A Solution to Improving Exercise Performance

Carbs are metabolized to glucose, which provides the body with blood sugar to give cells the energy they need to function.  However, the human body can store carbs for approximately 2 hours of exercise.3  Soon after, fatigue and decreased exercise performance may result.  So what did athletes do?  The typical response is something like: “Hey, if I’m not eating enough carbs to last me the time I need, why don’t I consume more?”  With that mindset, endurance athletes turned to eating a lot of carbs the day before they needed to compete in a process known as “carb loading.”  Scientist are now finding that there is a better solution to this problem.

The Value of Fat vs. Carbs

Researchers have proposed the use of fat as fuel to enhance sports performance.  During exercise, this medium offers more energy at lower intensities opposed to carbs which provide energy at high intensities.  They found that low-carb diets not only help you burn more fat when fat is consumed, but also prevent fatigue in prolonged exercise.4

Weight Loss and Body Fat Percentages

The keto diet causes the body to burn both consumed fat and stored fat more efficiently, which results in lower body fat percentages. In a study considering the effects of the keto diet on body composition, it was demonstrated that the participants had lost an average of 4.0 kg in 10 weeks through body fat.5

Ketosis may be the solution to the needs of endurance athletes concerned with maintaining higher energy levels to tap into for peak performance levels for longer periods of time.  It may also be useful for the average person looking to lose weight while remaining healthy and full of energy.  It’s everything you’d need and more!


The content on this website should not be taken as medical advice and you should ALWAYS consult with your doctor before starting any diet or exercise program. We provide nutritional data for our recipes as a courtesy to our readers. We use Total Keto Diet app software to calculate the nutrition and we remove fiber and sugar alcohols, like erythritol, from the total carbohydrate count to get to the net carb count, as they do not affect your blood glucose levels. You should independently calculate nutritional information on your own and not rely on our data. The website or content herein is not intended to cure, prevent, diagnose or treat any disease. This website shall not be liable for adverse reactions or any other outcome resulting from the use of recipes or recommendations on the Website or actions you take as a result. Any action you take is strictly at your own risk.

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