Photo by Tom Sharrow/

The most challenging part of a successful keto diet is getting over that first hump and becoming “fat-adapted.” A fat-adapted body has accustomed itself to burning stored fat, instead of carbs, for energy. This transition period can be accompanied by the much-feared “keto flu,” and is generally what wards off potential dieters. However, fatigue and headaches at the start are the normal result of your body’s withdrawal from its dependence on carbs. When paired with the right kind of exercise, a successful transition can produce extraordinary weight loss results.

Fat-Adapted and the End of Craves

This transition stage is the hardest part of the keto diet. As with any withdrawal period, however, it comes to an end. During this process our brains crave the sugar fix they get from our normal carb intake before finally learning to rely on fat for the body’s primary source of energy.1 The fat-adapted body has not only learned to use the ketones produced by carb deprivation for energy but stops craving carbs with such intensity. As cravings subside, overall appetite adjusts to the new diet, and the body learns to satiate itself on its own fat stores.

Low Intensity Exercise

According to Dr. Jeff Volek, the “keto-adapted” athlete (as he puts it) has access to a much more sustainable source of energy throughout the workout. Once the crave for carbs before exercise is gone, your body can focus on burning fat rather than simultaneously digesting and using up carbs. But what kind of exercise is best suited to the fat-adapted body? According to Volek, fatty acids and ketones becomes the body’s main source of energy during “submaximal exercise.”2

The growing body of research on keto dieting and exercise backs up these claims. A 2004 study found that a low carb diet is sustainable and indeed can be preferred for high endurance athletes, such as marathon runners.3 The ample amounts of stored fat in the body provide a reliable long-term energy source, while carbs provide a quick fix more suitable to strength and power athletes. A 2016 study in the journal Metabolism reinforces these claims, having found that long-distance runners with fat-adapted bodies burned twice the amount of fat as their carb-burning counterparts.4

For those looking to burn fat on the keto diet, such low-intensity endurance exercise is probably the most efficient method when combined with new eating habits. But give your body time to recognize and adapt to its new energy source before hitting the track.


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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